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SIGNIFICANCE Paralympic judo currently requires all athletes to compete against each other in one class irrespective of their level of vision impairment (VI). Recent evidence suggests that multiple classes are required to enhance fairness, yet it remains unclear how many classes are necessary and what vision tests should be used to define those classes. PURPOSE The aim of this study was to quantify the relationship between vision and performance in judo for individuals with VI. The results were expected to inform the development of evidence-based criteria to structure Paralympic judo competition. METHODS The visual function of 53 elite VI judokas was assessed using a test battery that included tests of visual acuity (VA), contrast sensitivity, light sensitivity, depth perception, motion perception, visual search, and central visual field. Performance was assessed by measuring the ratio of fights won across all competitions the participants took part in in the 2 years before and after vision testing. Pearson correlation coefficients and decision tree analyses were used to determine the relationship between vision and performance. Partial correlations were also conducted to determine the unique ability of each measure of visual function to predict judo performance. RESULTS Visual acuity was the best predictor of judo performance and remained the only visual function related to performance when controlling for correlations between VA and other visual functions. Decision tree analyses suggested to split athletes into two groups for more legitimate competition, using a cutoff point around 2.6 logMAR. Within each of the two resulting subgroups, no correlations remained between any of the visual functions and performance. CONCLUSIONS The results of this study suggest that VI judo competition should be split into separate categories for partially sighted and functionally blind athletes. The inclusion of visual functions in addition to VA does not improve the ability to predict performance in VI judo.

SIGNIFICANCE This review summarizes the main factors of refractive error after silicone oil removal combined with cataract surgery.The post-operative refractive results of silicone oil removal combined with cataract surgery are closely related to the patient's future vision quality. This report summarizes the factors that influence the difference between the actual post-operative refractive power and the pre-operatively predicted refractive power after silicone oil removal combined with cataract surgery, including axial length, anterior chamber depth, silicone oil, commonly used tools for measuring intraocular lens power, and intraocular lens power calculation formulas, among others. The aim of the report is to assist clinical and scientific research on the elimination of refractive error after silicone oil removal combined with cataract surgery.

SIGNIFICANCE The present study addresses the accommodative response and its dependence on the type of optical correction used. The results are discussed relative to their possible implications for myopia progression and visual fatigue. PURPOSE The accommodative response has been investigated owing to its possible relationship with the onset and progression of myopia and visual fatigue. This study explored the influence of wearing soft contact lenses in comparison with spectacles in terms of magnitude and variability of accommodation. In addition, we analyzed the intersession and intermethod repeatability. METHODS Dynamic accommodative response was recorded during 30-second epochs, at five different distances (50, 40, 33, 25, and 20 cm), in 21 individuals (mean refractive error ± SD, -0.79 ± 1.39 D) while wearing either soft contact lenses or spectacles on two different days. To assess repeatability, a second identical intervention was conducted. RESULTS Higher lags of accommodation were obtained with the use of soft contact lenses in comparison with the spectacle condition (P =.04, partial η 2 [η p 2] = 0.204), and similarly, a higher variability of accommodation at near distances was found during the soft contact lens measurement (P

SIGNIFICANCE: Uncorrected refractive error is the leading cause of visual impairment; therefore, reducing its prevalence is important worldwide. For two decades, there has not been a comprehensive assessment of refractive error in Latin America. PURPOSE: The purpose of this study was to determine the current prevalence of refractive error, presbyopia, spectacle coverage, barriers to uptake refractive services, and spectacle correction in people 15 years and older in Bogotá, Colombia. METHODS: A cross-sectional community-based survey was conducted using 50 randomly selected clusters from 10 districts of Bogotá reflecting the socioeconomic status of the city. Respondents 15 years and older were interviewed and underwent standardized clinical eye examinations. Prevalence of uncorrected refractive error, spectacle coverage, and visual impairment were standardized to 2015 age-sex population distribution of Bogotá and further analyzed. RESULTS: A total of 2886 subjects (90% of 3206 eligible subjects) participated in the study; 39.1% were male and 60.9% were female in the age range of 15 to 96 years, with a median age of 46 years (interquartile range, 45 to 54 years). Age- and sex-standardized prevalence of visual impairment was 19.3% (95% confidence interval [CI], 17.8 to 20.8%). Prevalence of uncorrected refractive error was 12.5% (95% CI, 11.3 to 13.7%). Prevalence of presbyopia among participants 35 years and older was 55.2% (95% CI, 52.9 to 57.4%). Spectacle coverage was 50.9% for distance vision, and it was 33.9% for presbyopia. Main barrier to spectacle uptake was a limitation in affording spectacles because of economic factors (29.5%). CONCLUSIONS: This study provides a current estimate of refractive error using the Rapid Assessment of Refractive Error for Colombia and the Latin American region. The prevalence of uncorrected refractive error and presbyopia was high, and the barriers to spectacle uptake were higher in the lowest socioeconomic strata. The results obtained in the present study will help in making evidence-based decisions related to eye care service delivery in Colombia.

SIGNIFICANCE Glaucoma has been shown to impair hazard detection ability and increase crash risk compared to controls. Differences in visual search behavior of the driving scene may explain these differences; however, there has been limited investigation of this issue with inconsistent findings. PURPOSE Through eye movement tracking of older drivers with glaucoma, we explored their visual search behavior in comparison with controls while performing the DriveSafe, a slide recognition test purported to predict fitness to drive. METHODS Thirty-one drivers with glaucoma (mean age, 71.7 ± 6.3 years; average better-eye mean defect,-3 dB; average worse-eye mean defect,-12 dB) and 25 age-matched controls underwent measurements of their visual acuity, contrast sensitivity, visual fields, and useful field of view (visual processing speeds). Participants' eye movements were recorded while they completed the DriveSafe test, which consists of brief presentations of static, real-world driving scenes containing various road users (pedestrians, bicycles, vehicles). Participants reported the types, positions, and direction of travel of road users in each image; the score was the total number of correctly reported items (maximum, 128). RESULTS Drivers with glaucoma had significantly worse DriveSafe scores (P = .03), fixated on road users for shorter durations (P < .001), and exhibited smaller saccades (P = .02) compared with controls. For all participants, longer fixation times on road users (P < .001) was the eye movement measure most strongly associated with better DriveSafe scores; this relationship was not significantly different between groups. Useful field-of-view divided attention was the strongest visual predictor of DriveSafe scores. CONCLUSIONS Eye movement changes in the glaucoma group may reflect increased difficulty in identifying relevant objects in the visual scene, which may be related to their lower DriveSafe scores. Given the DriveSafe's potential utility in assessing drivers with visual impairment before on-road testing, further investigations on how DriveSafe performance and eye movement patterns compare to those during on-road driving are warranted.

Significance Self-adjustable spectacles are increasingly being used in refractive service delivery programs in developing countries. Despite the success of self-refraction as a refraction technique, compliance with actual wear of adjustable spectacles has not been evaluated. Findings in this study have significant programmatic implications for the effectiveness and sustainability of this mode of correction in developing countries. Purpose The purpose of this study was to assess compliance with wearing of adjustable spectacles and factors associated with compliance in pre-teen schoolchildren at 6 months after spectacles were dispensed. Methods A cohort of 86 children aged 6 to 12 years with presenting vision worse than or equal to 6/12 in the better eye that could be improved to better than or equal to 6/7.5 by subjective refraction and who were identified from a randomized sample of 18 primary schools in the coastal areas of Cape Coast in Ghana received free FocusSpecs adjustable spectacles after successfully completing self-refraction and cycloplegic subjective refraction. Follow-up examination to assess compliance and to determine reasons for noncompliance was conducted at 6 months after spectacle provision. Logistic regression models assessed factors associated with spectacle wear compliance (95% confidence intervals [CIs]). Results Spectacle wear compliance was 33.7% (95% CI, 31.3 to 36.1%); an additional 29% had their spectacles with them but were not wearing them. The major reasons given by the children for noncompliance were "loss" (32%; 18/57) and "breakage" (23%; 13/57). Modest compliance (49%) was observed among the poorer children who attend public schools. Attending public school was the only predictor of compliance to spectacle wear (odds ratio, 3.096; 95% CI, 1.228 to 7.805; P = .02). Conclusions Despite accurate self-refraction by most children, only a small proportion was compliant with actual wear of the spectacles. Loss and breakage were the major reasons for noncompliance. The poorer children who attend public schools, who stand to benefit most from the technology, were the ones more likely to be compliant with wear.

Significance Well-established charts such as Early Treatment Diabetic Retinopathy Study are able to quantify visual acuity (VA) with a low cutoff of 1.6 logMAR. Below this point, nonquantitative measures, such as count fingers, hand movements, and light perception, are used. There is a need for more reproducible, comparable, and reliable ways to measure VA changes in this patient cohort. Purpose The purpose of this study was to examine and compare the ability of the Berkeley Rudimentary Vision Test (BRVT) and the Freiburg Acuity Test (FrACT) to quantify VA in low-vision patients who score nonnumerical VAs in standard charts. Methods Fifty adult participants with VA ≤1.0 logMAR in both eyes were recruited from the Oxford Eye Hospital, Oxford, United Kingdom. Correlation between FrACT and BRVT results and the correlation between VA and daily living activities were analyzed statistically. Potential predictors of differences were investigated. Results The BRVT was significantly faster to conduct (P = .002), but FrACT was able to quantify vision numerically in a greater proportion of eyes. The κ agreement between tests was 0.26. The difference increased systematically with the VA reduction (P < .0001). The Bland-Altman analysis showed a skew to measurement of lower logMAR VA indicating better vision measured on the FrACT. The only significant predictor of difference between the tests was binocular VA (coefficient, −0.445; P = .001). Conclusions Both tests are suitable for a very low-vision population. The BRVT is a faster test to administer, but FrACT provides a numerical result in more eyes. The poor intertest repeatability indicates that they cannot be used interchangeably. The BRVT generally reported poorer vision than did the FrACT. The medium of presentation, such as a computer screen or externally lit print medium, is likely to be the biggest factor in these differences and warrants further investigation.

Significance Full-field prisms that fill the entire spectacle eye wire have been considered as field expansion devices for homonymous hemianopia (HH) and acquired monocular vision (AMV). Although the full-field prism is used for addressing binocular dysfunction and for prism adaptation training after brain injury as treatment for spatial hemineglect, we show that the full-field prism for field expansion does not effectively expand the visual field in either HH or AMV. Purpose Full-field prisms may shift a portion of the blind side to the residual seeing side. However, foveal fixation on an object of interest through a full-field prism requires head and/or eye rotation away from the blind side, thus negating the shift of the field toward the blind side. Methods We fit meniscus and flat full-field 7Δ and 12Δ yoked prisms and conducted Goldmann perimetry in HH and AMV. We compared the perimetry results with ray tracing calculations. Results The rated prism power was in effect at the primary position of gaze for all prisms, and the meniscus prisms maintained almost constant power at all eccentricities. To fixate on the perimetry target, the subjects needed to turn their head and/or eyes away from the blind side, which negated the field shift into the blind side. In HH, there was no difference in the perimetry results on the blind side with any of the prisms. In AMV, the lower nasal field of view was slightly shifted into the blind side with the flat prisms, but not with the meniscus prisms. Conclusions Full-field prisms are not an effective field expansion device owing to the inevitable fixation shift. There is potential for a small field shift with the flat full-field prism in AMV, but such lenses cannot incorporate refractive correction. Furthermore, in considering the apical scotoma, the shift provides a mere field substitution at best.

SIGNIFICANCE In certain scenarios, it is advantageous to misrepresent one's ability and "cheat" on vision tests. Our findings suggest that increased variability when testing visual acuity holds promise as a novel means to help detect this cheating and may generalize to other subjective tests of visual function. PURPOSE People who cheat on vision tests generally do so to make their vision appear better than it actually is (e.g., for occupational or driving purposes). However, there are particular settings in which it is advantageous for their vision to appear to be worse than is the case (e.g., to qualify for benefits available to people with low vision). Therefore, a method to help detect cheating in these scenarios is desirable. The aim of this study was to investigate whether the intentional underrepresentation of vision could be detected when testing visual acuity. METHODS We tested the visual acuity of 13 participants with simulated vision impairment using the Berkeley Rudimentary Vision Test. Participants were tested in an honest condition when providing their best effort and in a cheating condition when attempting to make their visual acuity appear to be markedly worse. We also tested visual acuity of 17 participants with a wide range of vision impairments. RESULTS Participants were successfully able to "cheat" on the tests; however, their responses were significantly more variable when cheating (P

SIGNIFICANCE Central motion perception, as assessed by minimum displacement detection, was reduced in highly myopic eyes. Peripheral motion detection may be influenced by myopia, particularly in the inferior-nasal retina. PURPOSE Motion discrimination is a complex visual task processed mainly via the magnocellular pathway. We investigated whether it is affected in myopia. METHODS Ninety young adults aged 18 to 28 years participated: 30 emmetropes (spherical equivalent refractions +1.00 to −0.50 diopters [D]), 30 low myopes −1.00 to −4.75 D) and 30 higher myopes (

SIGNIFICANCE Growing popularity of handheld digital devices imposes significant challenges to our visual system and clinical management. This study aimed to determine the effects of lens design on parameters that may influence the refractive management of pre-presbyopic adult computer users. PURPOSE To determine the effects of wearing conventional single-vision lenses (SVL) versus progressive addition lenses (PAL) on the working distance and refractive status. METHODS Adult computer users, recruited from two age cohorts (18 to 25 years, n = 19; 30 to 40 years, n = 45), were prescribed SVLs and PALs designed for use with handheld digital devices. For each lens type, the working distance and refractive shift (post-task − pre-task) were measured immediately after lens delivery (T0) and after 1 month of lens wear (T1). Working distances were recorded with an automatic ultrasound device while the participants were playing a video game. Refractive status through the subjects' glasses was measured before (pre-task) and after playing the game (post-task). Questionnaires assessing the frequencies of 10 digital work–related visual symptoms were conducted for both lens types at T1. RESULTS Switching from SVL to PAL increased the working distance in both cohorts (mean ± SEM = 1.88 ± 0.60 cm; P = .002) and induced a small but significant positive refractive shift (+0.08 ± 0.04 D, P = .021) in the older cohort at T1. In the younger cohort, the changes in working distance due to the switching lens design were correlated with myopic error (r = +0.66, P = .002). In the older cohort, the changes in refractive shift due to switching lens design were correlated with amplitude of accommodation at both time points (r for T0 and T1 = −0.32 and −0.30, respectively; both P < .05). Progressive addition lens was rated as causing less “increased sensitivity to light” compared with SVL. CONCLUSIONS Switching from SVL to PAL increased the working distance and induced a positive refractive shift in the majority of pre-presbyopic adults.

SIGNIFICANCE: These results demonstrate that accommodation in children is more accurate and less variable when performing a sustained near task with increased cognitive demand. Additionally, children with increased uncorrected hyperopia have less stable accommodative responses, which may have visual implications during sustained near tasks. PURPOSE: This study investigated accommodative accuracy (lag) and variability during sustained viewing for passive and active tasks in children and adults with emmetropia and uncorrected hyperopia. METHODS: Lag and variability (root mean square [RMS] and low-frequency component) were measured in 54 children aged 3 to 0.05), but low-frequency component was larger during passive viewing (P=0.04). Group 1 had significantly higher RMS and low-frequency component than Group 2 and the adults in the passive condition and greater low-frequency component in the active condition. In children, hyperopia was independently associated with RMS and low-frequency component under passive (RMS 95% CI: 0.04–0.15, low-frequency component 95% CI: 0.00011–0.00065) and active (RMS 95% CI: 0.001–0.06, 95% CI: 0.000014–0.00023) viewing. CONCLUSIONS: Accommodation is more accurate and less variable when children are engaged in the task. Children also have more variable accommodation than adults. Additionally, children with greater hyperopia have more variable accommodation during sustained near tasks.

SIGNIFICANCEAmong 4- and 5-year-old children, deficits in measures of attention, visual-motor integration (VMI) and visual perception (VP) are associated with moderate, uncorrected hyperopia (3 to 6 diopters [D]) accompanied by reduced near visual function (near visual acuity worse than 20/40 or ste

Supplemental digital content is available in the text., SIGNIFICANCE This report describes the first clinical use of the Ohio Contrast Cards, a new test that measures the maximum spatial contrast sensitivity of low-vision patients who cannot recognize and identify optotypes and for whom the spatial frequency of maximum contrast sensitivity is unknown. PURPOSE To compare measurements of the Ohio Contrast Cards to measurements of three other vision tests and a vision-related quality-of-life questionnaire obtained on partially sighted students at Ohio State School for the Blind. METHODS The Ohio Contrast Cards show printed square-wave gratings at very low spatial frequency (0.15 cycle/degree). The patient looks to the left/right side of the card containing the grating. Twenty-five students (13 to 20 years old) provided four measures of visual performance: two grating card tests (the Ohio Contrast Cards and the Teller Acuity Cards) and two letter charts (the Pelli-Robson contrast chart and the Bailey-Lovie acuity chart). Spatial contrast sensitivity functions were modeled using constraints from the grating data. The Impact of Vision Impairment on Children questionnaire measured vision-related quality of life. RESULTS Ohio Contrast Card contrast sensitivity was always less than 0.19 log10 units below the maximum possible contrast sensitivity predicted by the model; average Pelli-Robson letter contrast sensitivity was near the model prediction, but 0.516 log10 units below the maximum. Letter acuity was 0.336 logMAR below the grating acuity results. The model estimated the best testing distance in meters for optimum Pelli-Robson contrast sensitivity from the Bailey-Lovie acuity as distance = 1.5 − logMAR for low-vision patients. Of the four vision tests, only Ohio Contrast Card contrast sensitivity was independently and statistically significantly correlated with students' quality of life. CONCLUSIONS The Ohio Contrast Cards combine a grating stimulus, a looking indicator behavior, and contrast sensitivity measurement. They show promise for the clinical objective of advising the patient and his/her caregivers about the success the patient is likely to enjoy in tasks of everyday life.

The amount of central or peripheral myopic shift, as induced by different multifocal contact lenses when viewing objects at distance or near, may provide insights on the potential efficacy for slowing eye growth.The present study aims to compare peripheral refraction and higher-order aberration profiles of four multifocal contact lenses with a single vision control lens.Thirty-five myopes (age 21.2 ± 2.1 years) completed the trial, of whom 16 wore Air Optix Aqua and Proclear Multifocal Distance and Near (Group 1, spherical equivalent: -2.90 ± 0.95D), whereas 19 wore Air Optix Aqua, Air Optix Multifocal, and PureVision Multifocal (Group 2, spherical equivalent: -2.95 ± 0.78D). Refraction and aberration profiles with lenses were measured using the BHVI-EyeMapper with (-2.00 to -5.00D in 1.00D steps) and without (+1.00D fogging) accommodation. Data were quantified using M2/4 (2nd and 2nd + 4th order), J0, J45, and higher-order aberration coefficients coma C[3, 1] and spherical aberration C[4, 0].The center-distance lens exhibited a relative peripheral myopic shift in M2/4 and J0, positive on-axis C[4, 0], negative on-axis C[3, 1] and on-axis M4 was less negative for accommodative demands ≤-3.00D (P.05). Inversely, the center-near lenses showed a relative peripheral hyperopic shift in M2/4 and J0, negative on-axis C[4, 0], positive on-axis C[3, 1] and on-axis M4 was more negative for demands of -2.00 and -3.00D (P.05). Independent of lens type, relative peripheral M4 significantly decreased during accommodation. Accounting for C[4, 0], a greater change in relative M profiles and accommodative responses was found for multifocal lenses.Based on the hypothesis that myopic retinal defocus counters eye growth, center-near multifocal lenses exhibited the preferred on-axis features, i.e., producing a central myopic shift at near compared to the control. The center-distance lens exhibited preferred off-axis features, producing relative peripheral myopia, which increased further during accommodation.

The Bifocal Lenses In Nearsighted Kids (BLINK) study is the first soft multifocal contact lens myopia control study to compare add powers and measure peripheral refractive error in the vertical meridian, so it will provide important information about the potential mechanism of myopia control.The BLINK study is a National Eye Institute-sponsored, double-masked, randomized clinical trial to investigate the effects of soft multifocal contact lenses on myopia progression. This article describes the subjects' baseline characteristics and study methods.Subjects were 7 to 11 years old, had -0.75 to -5.00 spherical component and less than 1.00 diopter (D) astigmatism, and had 20/25 or better logMAR distance visual acuity with manifest refraction in each eye and with +2.50-D add soft bifocal contact lenses on both eyes. Children were randomly assigned to wear Biofinity single-vision, Biofinity Multifocal "D" with a +1.50-D add power, or Biofinity Multifocal "D" with a +2.50-D add power contact lenses.We examined 443 subjects at the baseline visits, and 294 (66.4%) subjects were enrolled. Of the enrolled subjects, 177 (60.2%) were female, and 200 (68%) were white. The mean (± SD) age was 10.3 ± 1.2 years, and 117 (39.8%) of the eligible subjects were younger than 10 years. The mean spherical equivalent refractive error, measured by cycloplegic autorefraction was -2.39 ± 1.00 D. The best-corrected binocular logMAR visual acuity with glasses was +0.01 ± 0.06 (20/21) at distance and -0.03 ± 0.08 (20/18) at near.The BLINK study subjects are similar to patients who would routinely be eligible for myopia control in practice, so the results will provide clinical information about soft bifocal contact lens myopia control as well as information about the mechanism of the treatment effect, if one occurs.

PURPOSE To describe clinical features in children diagnosed with posterior polymorphous corneal dystrophy (PPCD) in their first or second decade of life. METHODS A retrospective study was performed with the medical records of seven unrelated Korean pediatric patients who were diagnosed with PPCD and were followed up for a minimum of 3 years. Thorough ocular examinations were performed, including best-corrected visual acuity, intraocular pressure, refractive and keratometric measurements, slit-lamp biomicroscopy, and specular microscopy at all visits. RESULTS Slit-lamp examinations revealed vesicular lesions in one patient and horizontally parallel band-like endothelial lesions in six patients. Unilateral corneal involvement was displayed in 4 patients, yielding 10 eyes with deep corneal features characteristic of PPCD. Other corneal, iris, or fundus pathologic findings were not detected in all cases. Among four children who were examined in their visual development (approximately under 8 years of age), two cases demonstrated unilateral amblyopia at initial examination and exhibited improved visual acuity after refractive correction and occlusion therapy. Astigmatism more than 1.5D, which is generally considered amblyogenic, was found in 8 among 10 PPCD-affected eyes. A final visual acuity of more than 20/32 was achieved with appropriate refractive correction in all PPCD-affected eyes. There was a negative correlation between the corneal astigmatism and the mean endothelial cell density (ECD) (r = -0.655, P = .011). Initial specular microscopic examinations revealed reduced ECD (1733.0 ± 543.9 cells/mm) composed of enlarged cells (average cell area, 624.8 ± 182.1 μm/cell) in PPCD-affected eyes, compared with those in PPCD-unaffected eyes from our study subjects (P < .001 and P = .005, respectively). A statistically significant percent loss in ECD from initial to 3 years was noted in the PPCD-affected eyes (P = .03). CONCLUSIONS The awareness and treatment of refractive error are important, especially in children with early-onset PPCD during the reversible period of amblyopia. Long-term monitoring of corneal endothelium is required in pediatric patients with early-onset PPCD based on a significant endothelial loss over 3 years in PPCD-affected eyes.

Purpose To investigate the effect of accommodation on central and peripheral axial lengths in young adult emmetropes and myopes. Methods On-axis and peripheral axial lengths were measured with the Haag-Streit Lenstar in 83 young adult participants for 0D and 6D accommodation demands. A Badal system was used to both correct refractive errors and induce accommodation. Participants were emmetropes (n = 29, mean spherical equivalent refraction +0.35 ± 0.35D), low myopes (32, -1.38 ± 0.73D), and higher myopes (22, -4.30 ± 0.73D). Ages were similar for all groups (22 ± 2 years). Pupils were dilated with 2.5% phenylephrine to allow a large field of measurement while maintaining active accommodation. Axial lengths were measured in 5° steps to ±30° across the horizontal visual field. Results With accommodation, axial length increased for all refractive groups at all positions, but with lessening effect away from fixation. Axial length changes were greater for higher myopes than for emmetropes on-axis (higher myopes 41 ± 14 μm, emmetropes 30 ± 12 μm, P =.005), for higher myopes than for low myopes at 30° nasal (P =.03), and for the higher myopes than for the other groups at 20° nasal (P

PURPOSE: To determine the frequency and types of vision disorders associated with concussion, and to determine the success rate of vision therapy for these conditions in two private practice settings. METHODS: All records over an 18-month period of patients referred for post-concussion vision problems were reviewed from two private practices. Diagnoses of vergence, accommodative, or eye movement disorders were based on pre-established, clinical criteria. Vision therapy was recommended based on clinical findings and symptoms. RESULTS: Two hundred eighteen patient records were found with a diagnosis of concussion. Fifty-six percent of the concussions were related to sports, 20% to automobile accidents, and 24% to school, work, or home-related incidents. The mean age was 20.5 years and 58% were female. Eighty-two percent of the patients had a diagnosis of an oculomotor problem [binocular problems (62%), accommodative problems (54%), eye movement problems (21%)]. The most prevalent diagnoses were convergence insufficiency (CI, 47%) and accommodative insufficiency (AI, 42%). Vision therapy was recommended for 80% of the patients. Forty-six per cent (80/175) either did not pursue treatment or did not complete treatment. Of the 54% (95/175) who completed therapy, 85% of patients with CI were successful and 15% were improved, and with AI, 33% were successful and 67% improved. Clinically and statistically significant changes were measured in symptoms, near point of convergence, positive fusional vergence, and accommodative amplitude. CONCLUSIONS: In this case series, post-concussion vision problems were prevalent and CI and AI were the most common diagnoses. Vision therapy had a successful or improved outcome in the vast majority of cases that completed treatment. Evaluation of patients with a history of concussion should include testing of vergence, accommodative, and eye movement function. Prospective clinical trials are necessary to assess the natural history of concussion-related vision disorders and treatment effectiveness. Language: en

To analyze the effect of decentration on the optical quality of two diffractive-refractive intraocular lenses, a bifocal and a trifocal, when displaced laterally (horizontal direction) from the center.The AT LISA 809M IOL (+3.75 D add) with two main foci and the AT LISA tri 839MP intraocular lens with three main foci (Carl Zeiss Meditec AG, Jena, Germany) were analyzed. The optical quality of the intraocular lenses was measured with the PMTF (power and modulation transfer function [MTF] measurement for refractive and diffractive intraocular lenses) optical bench (Lambda-X, Nivelles, Belgium). The optical quality of the lenses was evaluated by the MTF at different object vergences, the average modulation in the range of frequencies from 0 to 100 cycles/mm, and the through-focus MTF curves. All measures were recorded when the intraocular lenses were centered and decentered for 3.0- and 4.5-mm apertures. The Strehl ratio and the percentage of energy allocated at each focus at the centered position were also obtained.Our results showed a lower optical quality with increasing decentration. The MTFs for the diffractive-refractive intraocular lenses decreased when the intraocular lenses were decentered. Also, the relative percentages of light energy allocated at each object vergence, for both intraocular lenses, agreed well with theoretical specifications and were consistent with the overall design of each lens.The optical quality of these diffractive-refractive multifocal intraocular lenses was slightly reduced when the induced decentration was less than 0.4 mm. For a decentration of 0.4 mm, the maximum difference in average modulation values was about 18% compared to the centered position.

PURPOSE To establish the repeatability and reproducibility of a virtual refraction process using simulated retinal images. METHODS With simulation software, aberrated images corresponding with each step of the refraction process were calculated following the typical protocol of conventional subjective refraction. Fifty external examiners judged simulated retinal images until the best sphero-cylindrical refraction and the best visual acuity were achieved starting from the aberrometry data of three patients. Data analyses were performed to assess repeatability and reproducibility of the virtual refraction as a function of pupil size and aberrometric profile of different patients. RESULTS SD values achieved in three components of refraction (M, J0, and J45) are lower than 0.25D in repeatability analysis. Regarding reproducibility, we found SD values lower than 0.25D in the most cases. When the results of virtual refraction with different pupil diameters (4 and 6 mm) were compared, the mean of differences (MoD) obtained were not clinically significant (less than 0.25D). Only one of the aberrometry profiles with high uncorrected astigmatism shows poor results for the M component in reproducibility and pupil size dependence analysis. In all cases, vision achieved was better than 0 logMAR. A comparison between the compensation obtained with virtual and conventional subjective refraction was made as an example of this application, showing good quality retinal images in both processes. CONCLUSIONS The present study shows that virtual refraction has similar levels of precision as conventional subjective refraction. Moreover, virtual refraction has also shown that when high low order astigmatism is present, the refraction result is less precise and highly dependent on pupil size.

PURPOSE To evaluate whether an induced astigmatism influences the subjective depth of focus. METHODS Fifty-one participants aged 18 to 35 years and with a mean spherical equivalent refractive error of -0.51 ± 2.35 DS participated in the study. The accommodation was blocked with three drops of 1% cyclopentolate. Refractive errors were corrected after subjective refraction with a 4-mm artificial pupil. To evaluate the depth of focus (DoF), defocus curves with a spherical range of ±1.5 DS were assessed. The DoF was calculated as the horizontal distance at a threshold level of +0.1 logMAR from the maximum visual acuity (VA). Defocus curves were estimated binocularly during distance (500 cm) and a near vision (40 cm) for two induced axis (ATR in 0° and WTR in 90°) and for a fixed amount of astigmatic defocus of -0.5 DC. RESULTS The mean natural DoF was 0.885 ± 0.316 D for far vision and 0.940 ± 0.400 D for near vision. With induced astigmatism, the DoF for far vision was significantly increased to 1.095 ± 0.421 D (p = 0.006, ANOVA) for the WTR astigmatism but not for the ATR astigmatism (1.030 ± 0.395 D; p = 0.164, ANOVA). The induced WTR astigmatism enhanced the DoF for near vision significantly to 1.144 ± 0.338 D (p = 0.04, ANOVA), and DoF with induced ATR astigmatism (0.953 ± 0.318 D) was not significantly different (p = 1.00, ANOVA). ATR-astigmatism reduced VA by +0.08 ± 0.08 logMAR (p < 0.01, t-test). CONCLUSIONS With an induced WTR astigmatism of -0.5 DC, the DoF can be enhanced in the near viewing distance with a marginal loss in binocular VA. The approach of using induced WTR astigmatism can lead to novel optical treatments for presbyopia.

PURPOSE Crowding, the increased difficulty in recognizing a target due to the proximity of adjacent objects, is identified as the main sensory constraint for the size of the visual span (the number of letters recognized without moving the eyes) and reading speed in peripheral vision. The goal of the present study is to assess the impact of temporal modulation on crowding, visual span, and reading in the periphery. METHODS Six normally sighted young adults participated in the study. Four temporal modulation patterns were examined: (1) moving scotoma (sequentially masking the component letters in a letter string or word), (2) moving window (sequentially presenting the component letters), (3) flashing (repeatedly masking and presenting all letters simultaneously), and (4) static (the control condition; no temporal changes during the presentation). For each condition, we obtained the spatial extent of crowding, the size of the visual span, and reading speeds measured by the rapid serial visual presentation method. RESULTS Compared with the static condition, the spatial extent of crowding was reduced in the moving window condition. Both the moving window and moving scotoma conditions led to a faster reading speed for print sizes smaller than critical print size (the smallest print size that allows maximum reading speed). However, none of the temporal modulations increased the size of the visual span and reading speed for print sizes larger than critical print size. CONCLUSIONS The results suggest that the temporal modulation patterns are of limited benefit for peripheral reading despite the substantial improvement for slow reading when print size is close to acuity threshold.

PURPOSE To quantify stereopsis at distance resulting from binocular fusion in patients with impaired binocular vision using a three-dimensional (3-D) display stereotest. METHODS A total of 68 patients (age range, 6 to 85 years) with strabismus (40 esotropes and 28 exotropes) whose stereoacuity could not be measured with the near and distance Randot stereotests were included. Contour-based circles with a wide range of crossed horizontal disparities (2500 to 20 arcsec) displayed on a 3-D monitor were presented to subjects at 3 m. Between the patients who had stereoacuity of at least 2500 arcsec and those with no measurable stereoacuity, parameters including age, sex, best-corrected visual acuity, spherical equivalent refractive error, Worth 4 dot test results, and type and angle of deviation were compared. RESULTS Stereoacuity at distance of 2500 arcsec or better was detected in 25 (63%) of 40 esotropes, and 16 (57%) of 28 exotropes, although stereoacuity of 800 arcsec or better was found only in two (5%) esotropes and one (4%) exotrope. Patients with stereopsis were significantly younger (19.3 ± 16.9 years) than those with no measurable stereopsis (31.5 ± 26.4 years) (p = 0.040). There were no significant differences in best-corrected visual acuity, presence of amblyopia >20/100, spherical equivalent refractive error, type of deviation, deviation angle, sex, and Worth 4 dot test results between these groups. CONCLUSIONS Stereopsis at distance resulting from binocular fusion that cannot be measured with conventional stereoacuity tests may be preserved in patients with impaired binocular vision. The 3-D display stereotest can be useful for quantifying stereopsis at distance resulting from binocular fusion.

UNLABELLED Supplemental digital content is available in the text. ABSTRACT To determine the benefits provided by centrally red-tinted contact lenses on visual acuity, contrast sensitivity (CS), photophobia, and quality of life in patients with degenerative retinal diseases.We evaluated the impact of centrally red-tinted hydrogel contact lenses on nine patients (aged 15 to 22 years) with severe photophobia and poor visual acuity. Each patient underwent a full eye examination with and without contact lenses, including visual acuity at distance and near, CS, eye movement recording for nystagmus, refraction, and a fundus examination. All patients completed a low vision-adapted VFQ 25-Version 2000 quality-of-life questionnaire.Seven of nine patients demonstrated improvement in binocular visual acuity as well as improvement in CS with the tinted contact lenses. Subjectively, all patients described a major improvement in their photophobia both outdoors and indoors, as well as a marked improvement in quality of life.Red-tinted contact lenses may dramatically improve visual functions, outdoor performance, and quality of life of patients suffering from retinal diseases. These lenses should be a part of the regular assessment in specialty clinics treating patients with low vision, glare, and photophobia.

Little is known about the prevalence of refractive error, binocular vision, and other visual conditions in Australian Indigenous children. This is important given the association of these visual conditions with reduced reading performance in the wider population, which may also contribute to the suboptimal reading performance reported in this population. The aim of this study was to develop a visual profile of Queensland Indigenous children.Vision testing was performed on 595 primary schoolchildren in Queensland, Australia. Vision parameters measured included visual acuity, refractive error, color vision, nearpoint of convergence, horizontal heterophoria, fusional vergence range, accommodative facility, AC/A ratio, visual motor integration, and rapid automatized naming. Near heterophoria, nearpoint of convergence, and near fusional vergence range were used to classify convergence insufficiency (CI).Although refractive error (Indigenous, 10%; non-Indigenous, 16%; p = 0.04) and strabismus (Indigenous, 0%; non-Indigenous, 3%; p = 0.03) were significantly less common in Indigenous children, CI was twice as prevalent (Indigenous, 10%; non-Indigenous, 5%; p = 0.04). Reduced visual information processing skills were more common in Indigenous children (reduced visual motor integration [Indigenous, 28%; non-Indigenous, 16%; p0.01] and slower rapid automatized naming [Indigenous, 67%; non-Indigenous, 59%; p = 0.04]). The prevalence of visual impairment (reduced visual acuity) and color vision deficiency was similar between groups.Indigenous children have less refractive error and strabismus than their non-Indigenous peers. However, CI and reduced visual information processing skills were more common in this group. Given that vision screenings primarily target visual acuity assessment and strabismus detection, this is an important finding as many Indigenous children with CI and reduced visual information processing may be missed. Emphasis should be placed on identifying children with CI and reduced visual information processing given the potential effect of these conditions on school performance.

Purpose To compare differences in contrast threshold among individual Sloan letters presented in additive white luminance noise and in the absence of noise. Methods Contrast threshold for letter identification was measured for three visually normal subjects (aged 22, 25, and 34 years) using letters from the Sloan set (C, D, H, K, N, O, R, S, V, and Z). The letter size was equivalent to 1.5 logMAR (logarithm of the minimum angle of resolution), and the letters were either unfiltered or band-pass filtered to limit the object frequency content (cycles per letter) to a one-octave wide band centered at 1.25, 2.5, 5, and 10 cycles per letter. Letters were presented for an unlimited duration against a uniform adapting field or in the presence of additive white luminance noise. Contrast threshold for each letter was determined using a 10-alternative forced-choice interleaved staircase procedure. Results For standard unfiltered Sloan letters presented against a uniform field, contrast threshold for individual letters differed by as much as a factor of 1.5, consistent with a previous report. When measured in luminance noise, the individual letters differed by as much as a factor of 1.8. Band-pass filtering the letters to include only low object frequencies increased the differences in contrast threshold among the individual letters (about a factor of 3) compared with unfiltered letters and letters filtered into high object frequency bands. Conclusions The addition of white luminance noise had relatively small effects on interletter contrast threshold differences, whereas band-pass filtering had large effects on interletter threshold differences, greatly increasing variation among the letters that contained only low object frequencies. Letters that contain only high object frequencies may be useful in the design of letter charts because the interletter threshold differences are relatively small for these optotypes and the object frequency information mediating identification is known.

Purpose It is well established that visual acuity (VA) decreases with luminance but the specific factors that are responsible remain unclear. The purpose of this study was to quantify the contributions of accommodative error, pupil size, and higher-order aberrations to the decrease in VA when transitioning from photopic to mesopic light levels. Additionally, repeatability of VA at photopic and mesopic levels was measured to derive a luminance recommendation for mesopic VA testing, which can provide the standardization needed for future translational clinical studies and the widespread adoption of mesopic VA testing. Methods Monocular VAs were assessed at one photopic and three mesopic light levels: 94, 3, 0.75, and 0.38 cd/m, with an E-ETDRS testing system in 43 normal subjects. Accommodative error, pupil size, and higher-order aberrations were obtained. Twenty subjects were retested at another visit to assess VA repeatability. Results The mean (±SD) logMAR (logarithm of the minimum angle of resolution) VA was -0.08 (±0.06) at 94 cd/m, 0.05 (±0.07) at 3 cd/m, 0.16 (±0.06) at 0.75 cd/m, and 0.27 (±0.09) at 0.38 cd/m. Light level and accommodative error were significantly associated with VA, and light level explained 75% of the variance. The mean differences in VAs between two visits were not significantly different from zero (p > 0.05). The coefficients of repeatability for 94, 3, 0.75, and 0.38 cd/m were 0.08, 0.11, 0.14, and 0.14 logMAR, respectively. Conclusions Light level, among all other factors studied, contributes the most to the reduction in VA tested under mesopic conditions. Testing mesopic VA at 0.75 cd/m, or about 2.0 log units less than photopic testing, provides a significant and repeatable decrease in VA similar to standardized low-contrast VA testing, and therefore this level is recommended.

PURPOSE: There are two currently available lantern tests that have their design based solely on the practices of the rail industry. These are the CN Lantern used on the Canadian Railways and the Railway LED Lantern Test (RLLT). In the same way that the signaling practices differ in the two jurisdictions, the design of the lanterns also differ. The CIE (Commission Internationale de l'Eclairage)-recommended color vision standards for transport predate both lanterns. The study was undertaken to assess the appropriateness of these lanterns in CIE Color Vision Standard 1. CIE Standard 1 is called "Normal color vision" but some very mild anomalous trichromats may pass the specified "lantern test that presents a high level of difficulty." METHODS: The lantern tests were undertaken by 46 color vision-normal and 37 color vision-deficient subjects. RESULTS: Subjects made more errors on the RLLT, and the pattern of errors is different, partly because there are blank presentations in the RLLT and "no light" is an acceptable response. The two lanterns showed agreement on the pass/fail categorization of 73 of the 83 subjects. The RLLT fails more color vision-normal subjects. CONCLUSIONS: Despite the different construction principles, the RLLT and Canadian Railways Lantern have pass/fail levels that are comparable with the Holmes-Wright Type B lantern, which is nominated in CIE Color Vision Standard 1 but is no longer commercially available. The higher failure rate of color vision-normal subjects on the RLLT has been addressed by changing the intensities of the two darkest red lights. Language: en

PURPOSE: Lantern tests and practical tests are often used in the assessment of prospective railway employees. The lantern tests rarely embody the actual colors used in signaling on the railways. Practical tests have a number of problems, most notably consistency of application and practicability. This work was carried out to provide the Railway LED Lantern Test (RLLT) as a validated method of assessing the color vision of railway workers. METHODS: The RLLT, a simulated practical test using the same LEDs (light-emitting diodes) as are used in modern railway signals, was developed. It was tested on 46 color vision-normal (CVN) and 37 color vision-deficient (CVD) subjects. A modified prototype was then tested on 106 CVN subjects. RESULTS: All 106 CVN subjects and most mildly affected CVD subjects passed the modified lantern at 3 m. At 6 m, 1 of the 106 normal color vision subjects failed by missing a single red light. All the CVD subjects failed. The RLLT carried out at 3 m allowed mildly affected CVD subjects to pass and demonstrate adequate color vision for the less demanding railway tasks. Carried out at 6 m, it essentially reinforced normal color vision as the standard. CONCLUSIONS: The RLLT is a simply administered test that has a direct link to the actual visual task of the rail worker. The RLLT lantern has been adopted as an approved test in the Australian National Standard for Health Assessment of Rail Safety Workers in place of a practical test. It has the potential to be a valid part of any railway color vision standard. Language: en

To compare the aberrometry-derived refractive error measurements from the IRX3 aberrometer (Imagine Eyes, Orsay, France) with a standardized measure of refractive error from the Shin-Nippon SRW-5000 (Japan) autorefractor in a large sample of school-aged children.Participants were a subgroup of children from the Northern Ireland Childhood Errors of Refraction Study phase 2 (n = 161 9 to 10 years; n = 147 15 to 16 years). Refractive error was measured under cycloplegia (1.0% cyclopentolate HCl) with the IRX3 aberrometer followed by measurement with the Shin-Nippon autorefractor. Mean differences and 95% confidence intervals and limits of agreement were calculated for refractive vector components (M, J0, and J45).Participants had a wide range of refractive error ranging from -6.00 to +8.00 diopters (D) spherical equivalent refraction. Fixed measurement biases (±95% confidence interval) between instruments were small for both groups (9- to 10-year-olds: M, -0.20 ± 0.65 D; J0, -0.005 D; J45, 0.05 D; 15- to 16-year-olds: M, 0.03 ± 0.61 D; J0, -0.04 D; J45, -0.02 D). Statistically significant differences were found between instruments for M and J45 for the 9- to 10-year-old group (p0.0001) and for J0 for the 15- to 16-year-old group (p = 0.003). A statistically significant proportional measurement bias was found for the cylindrical components J0 and J45 for both groups (p0.0001), but no statistically significant proportional bias was found for M for either group.This is the first study to explore refractive error measurements from the IRX3 aberrometer in children. The differences between instruments for all refractive components (M, J0, and J45) were small for both groups (0.25 D) and may not be considered clinically meaningful. Levels of agreement were also comparable to other studies investigating the validity of instruments measuring automated refraction in both adults and children. The results would suggest that these objective techniques produce similar results for assessment of refractive error in children.

To determine demographic and refractive risk factors for astigmatism in the Vision in Preschoolers Study.Three- to 5-year-old Head Start preschoolers (N = 4040) from five clinical centers underwent comprehensive eye examinations by study-certified optometrists and ophthalmologists, including monocular visual acuity testing, cover testing, and cycloplegic retinoscopy. Astigmatism was defined as the presence of greater than or equal to +1.5 diopters (D) cylinder in either eye, measured with cycloplegic refraction. The associations of risk factors with astigmatism were evaluated using the odds ratio (OR) and its 95% confidence interval (CI) from logistic regression models.Among 4040 Vision in Preschoolers Study participants overrepresenting children with vision disorders, 687 (17%) had astigmatism, and most (83.8%) had with-the-rule astigmatism. In multivariate analyses, African American (OR, 1.65; 95% CI, 1.22 to 2.24), Hispanic (OR, 2.25; 95% CI, 1.62 to 3.12), and Asian (OR, 1.76; 95% CI, 1.06 to 2.93) children were more likely to have astigmatism than non-Hispanic white children, whereas American Indian children were less likely to have astigmatism than Hispanic, African American, and Asian children (p0.0001). Refractive error was associated with astigmatism in a nonlinear manner, with an OR of 4.50 (95% CI, 3.00 to 6.76) for myopia (≤-1.0 D in spherical equivalent) and 1.55 (95% CI, 1.29 to 1.86) for hyperopia (≥+2.0 D) when compared with children without refractive error (-1.0 D,+2.0 D). There was a trend of an increasing percentage of astigmatism among older children (linear trend p = 0.06). The analysis for risk factors of with-the-rule astigmatism provided similar results.Among Head Start preschoolers, Hispanic, African American, and Asian race as well as myopic and hyperopic refractive error were associated with an increased risk of astigmatism, consistent with findings from the population-based Multi-ethnic Pediatric Eye Disease Study and the Baltimore Pediatric Eye Disease Study. American Indian children had lower risk of astigmatism.

Purpose. To investigate the association of hyperopia greater than +3.25 diopters (D) with amblyopia, strabismus, anisometropia, astigmatism, and reduced stereoacuity in preschoolers. Methods. Three- to five-year-old Head Start preschoolers (N = 4040) underwent vision examination including monocular visual acuity (VA), cover testing, and cycloplegic refraction during the Vision in Preschoolers Study. Visual acuity was tested with habitual correction and was retested with full cycloplegic correction when VAwas reduced below age norms in the presence of significant refractive error. Stereoacuity testing (Stereo Smile II) was performed on 2898 children during study years 2 and 3. Hyperopia was classified into three levels of severity (based on the most positive meridian on cycloplegic refraction): group 1: greater than or equal to +5.00 D, group 2: greater than +3.25 D to less than +5.00 D with interocular difference in spherical equivalent greater than or equal to 0.50 D, and group 3: greater than +3.25 D to less than +5.00 D with interocular difference in spherical equivalent less than 0.50 D. ‘‘Without’’ hyperopia was defined as refractive error of +3.25 D or less in the most positive meridian in both eyes. Standard definitions were applied for amblyopia, strabismus, anisometropia, and astigmatism. Results. Relative to children without hyperopia, children with hyperopia greater than +3.25 D (n = 472, groups 1, 2, and 3) had a higher proportion of amblyopia (34.5 vs. 2.8%, p G 0.0001) and strabismus (17.0 vs. 2.2%, p G 0.0001). More severe levels of hyperopia were associated with higher proportions of amblyopia (51.5% in group 1 vs. 13.2% in group 3) and strabismus (32.9% in group 1 vs. 8.4% in group 3; trend p G 0.0001 for both). The presence of hyperopia greater than +3.25 D was also associated with a higher proportion of anisometropia (26.9 vs. 5.1%, p G 0.0001) and astigmatism (29.4 vs. 10.3%, p G 0.0001). Median stereoacuity of nonstrabismic, nonamblyopic children with hyperopia (n = 206) (120 arcsec) was worse than that of children without hyperopia (60 arcsec) (p G 0.0001), and more severe levels of hyperopia were associated with worse stereoacuity (480 arcsec for group 1 and 120 arcsec for groups 2 and 3, p G 0.0001). Conclusions. The presence and magnitude of hyperopia among preschoolers were associated with higher proportions of amblyopia, strabismus, anisometropia, and astigmatism and with worse stereoacuity even among nonstrabismic, nonamblyopic children. (Optom Vis Sci 2014;91:383Y389)

Purpose. To explore the effectiveness of combining uncorrected visual acuity (UCVA) and noncycloplegic autorefraction (NCAR) for large-scale myopia screening in schoolchildren with a high prevalence of myopia. Methods. A total of 1687 children aged between 6 and 12 years, from five primary schools in the Baoshan district of Shanghai participated in the study. We measured UCVA and autorefraction before and after cycloplegia by a Topcon KR-8800. We drew receiver operating characteristic curves to achieve the best cutoff points and their corresponding sensitivities and specificities for the UCVA and NCAR, respectively. We then combined the UCVA and NCAR in serial order to explore the optimal criterion and its effectiveness. A specificity of 90% was set to compare the sensitivities among the three tests. The children were divided into three age groups (aged 6 to 7, 8 to 10, 11 to 12 years) to further examine this new method. Results. A total of 1639 children with an average age of 9.35 (SD, 1.6) years were finally included, among which 428 (26.11%) children were diagnosed as being myopic (spherical equivalent refraction (SER) less than or equal to j0.5 diopters [D]). For the UCVA, the cutoff point is 0.2 logarithm of the minimum angle of resolution (20/32), with a sensitivity and specificity of 63.6% and 94.0%, respectively. For NCAR, the cutoff point is SER less than or equal to j0.75 D, with a sensitivity and specificity of 88.6% and 86.1%, respectively. When UCVA is combined with NCAR, the best cutoff point is UCVA less than or equal to 0 logarithm of the minimum angle of resolution (20/20) and SER less than or equal to j0.75 D, with a sensitivity and specificity of 84.4% and 90.5%, respectively. At a specificity of 90%, the sensitivities are 63.55%, 78.50%, and 84.35%, respectively, for UCVA, NCAR, and the combination test. In all age groups, the combination test had the highest sensitivities among the three tests. Conclusions. In a population with a high prevalence of myopia, combining the UCVA and NCAR in serial order achieved higher sensitivity than either of the two tests alone, when specificity was set at 90%. (Optom Vis Sci 2013;90:00Y00)

Purpose. To compare visual acuity (VA) assessed in healthy eyes and eyes with diabetic retinopathy (DR) using three different logMAR charts: the Sloan letter European-wide chart, the tumbling E chart, and the Landolt C chart. Methods. Measurements on one eye of 40 volunteers (aged 29 T 4 years) without visual impairment and 31 DR patients (aged 70 T 9 years) with mild/moderate visual impairment were included. Visual acuity was assessed, with habitual refractive correction, using each of the three charts. Bland-Altman charts were constructed, and 95% limits of agreement were calculated to measure agreement. Results. Mean VA in the group of young adults was j0.05 T 0.10 (Sloan letter), j0.02 T 0.13 (tumbling E), and 0.00 T 0.12 (Landolt C) logMAR. Average VA estimates differed to a statistically significant extent between all charts. Mean VA in the DR group was 0.46 T 0.25 (Sloan letter), 0.48 T 0.26 (tumbling E), and 0.59 T 0.28 (Landolt C). A statistically significant difference was observed for average Sloan letter versus Landolt C (p G 0.001) and tumbling E versus Landolt C (p G 0.001) acuities. Moreover, in healthy eyes, a moderate correlation (r = j0.38, p = 0.015) was found between the discrepancy in Sloan letter and Landolt C acuity and the mean VA estimate. The 95% limits of agreement were wide (more than approximately 0.2 logMAR for each comparison) and wider in the DR group chart comparisons than in healthy eyes. Conclusions. Landolt C charts resulted in worse VA estimates compared with letter and tumbling E charts in both young adults and visually impaired subjects with DR. These differences seem more pronounced in DR patients who exhibit worse VAs. The specific study population must be considered in comparing outcomes from different clinical practices. (Optom Vis Sci 2013;90:00Y00)

Purpose: Inaccurate accommodation during nearwork and subsequent accommodative hysteresis may influence myopia development. Myopia is highly prevalent in Singapore; an untested theory is that Chinese children are prone to these accommodation characteristics. We measured the accuracy of accommodation responses during and nearwork-induced transient myopia (NITM) after periods spent reading Chinese and English texts. Methods: Refractions of 40 emmetropic and 43 myopic children were measured with a free-space autorefractor for four reading tasks of 10-minute durations: Chinese (SimSun, 10.5 points) and English (Times New Roman, 12 points) texts at 25 cm and 33 cm. Accuracy was obtained by subtracting accommodation response from accommodation demand. Nearwork-induced transient myopia was obtained by subtracting pretask distance refraction from posttask refraction, and regression was determined as the time for the posttask refraction to return to pretask levels. Results: There were significant, but small, effects of text type (Chinese, 0.97 ± 0.32 diopters [D] vs. English, 1.00 ± 0.37 D; F1,1230 = 7.24, p = 0.007) and reading distance (33 cm, 1.01 ± 0.30 D vs. 25 cm, 0.97 ± 0.39 D; F1,1230 = 7.74, p = 0.005) on accommodation accuracy across all participants. Accuracy was similar for emmetropic and myopic children across all reading tasks. Neither text type nor reading distance had significant effects on NITM or its regression. Myopes had greater NITM (by 0.07 D) (F1,81 = 5.05, p = 0.03) that took longer (by 50s) (F1,81 = 31.08, p < 0.01) to dissipate. Conclusions: Reading Chinese text caused smaller accommodative lags than reading English text, but the small differences were not clinically significant. Myopic children had significantly greater NITM and longer regression than emmetropic children for both texts. Whether differences in NITM are a cause or consequence of myopia cannot be answered from this study.

PURPOSE: Population-based studies on abnormal binocular vision and low literacy are rare. The aim is to determine the prevalence of poor stereoacuity among children with low literacy; to identify the characteristics associated with poor stereoacuity among children with low literacy; and to determine the agreement between poor stereoacuity as measured by graded stereocircles with a computerized assessment. METHODS: A total of 490 children attending primary school in the greater Hobart region, Tasmania, aged 7 to 14 years, with literacy results below the 10th percentile for Tasmanian students at grade 3 level of the NAPLAN (National Assessment Program in Literacy and Numeracy) testing completed a vision screen. Poor stereoacuity was defined as more than 100 seconds of arc as measured by Titmus stereocircles. RESULTS: The prevalence of poor stereoacuity was 16.8% (95% confidence interval [95% CI], 13.6 to 20.4%). Children with poor stereoacuity had a higher frequency of symptom report using the Convergence Insufficiency Symptom Survey. Factors associated with poor stereopsis were prematurity (adjusted odds ratio [AOR], 2.19; 95% CI, 1.09 to 4.42) and bottom shuffling (AOR, 2.39; 95% CI, 1.17 to 4.88). Features associated with poor stereopsis included squint (AOR, 6.05; 95% CI, 3.02 to 12.12), migraine (AOR, 2.25; 95% CI, 1.05 to 4.83), and attention deficit disorder (AOR, 1.92; 95% CI, 1.01 to 3.65). CONCLUSIONS: In this low-literacy sample, one-sixth had low stereoacuity. The associations reported require further investigation.Copyright © 2013 American Academy of Optometry.

Purpose Dissociated horizontal deviation (DHD), a rare subtype of strabismus, is a change in horizontal eye alignment that does not obey Hering’s law. The variation is unrelated to a change in accommodation and depends on which eye is fixating. Both esotropia (ET) and exotropia (XT) can manifest in the same patient with DHD. Surgery has been reported to manage DHD, but often a second or third surgery is necessary. We report two cases of DHD that were managed with vision therapy (VT). Case reports Case one: A 9-year-old girl presented for eye examination with her parents noting an eye drifting out. Cover test showed a DHD that varied from 15Δ left ET to 15Δ alternating XT. A 40Δ XT manifested when she was inattentive. Antisuppression, vergence, accommodation, and oculomotility were addressed with VT. Upon completion of VT, binocular vision functions were normal except for appreciation of global stereopsis. No strabismus was observed during the examination. These findings were stable at a 7-month follow-up visit. Case two: A 40-year-old man presented for eye examination with the complaint of double vision and eye strain. Cover test revealed a DHD that varied from 5Δ ET to 15Δ XT, along with DVD. A 30 to 40Δ XT was observed during visual inattention. Antisuppression and vergence skills were addressed with VT. At the end of VT, most binocular vision functions were normal. No strabismus was observed on cover test. Follow-up examination 16 years later showed no strabismus by cover test, although XT manifested when he was inattentive. Conclusions In two DHD cases, control of eye alignment improved with VT. To the best of our knowledge, these are the first case reports to describe management of DHD with VT. Eye care practitioners should be aware that a long period of VT may be necessary to successfully manage DHD.

Purpose This study compared three different methods of determining a reading addition and the possible improvement on reading performance in children and young adults with low vision. Methods Twenty-eight participants with low vision, aged 8 to 32 years, took part in the study. Reading additions were determined with (a) a modified Nott dynamic retinoscopy, (b) a subjective method, and (c) an age-based formula. Reading performance was assessed with MNREAD-style reading charts at 12.5 cm, with and without each reading addition in random order. Outcome measures were reading speed, critical print size, MNREAD threshold, and the area under the reading speed curve. Results For the whole group, there was no significant improvement in reading performance with any of the additions. When participants with normal accommodation at 12.5 cm were excluded, the area under the reading speed curve was significantly greater with all reading additions compared with no addition (p = 0.031, 0.028, and 0.028, respectively). Also, the reading acuity threshold was significantly better with all reading additions compared with no addition (p = 0.014, 0.030, and 0.036, respectively). Distance and near visual acuity, age, and contrast sensitivity did not predict improvement with a reading addition. All, but one, of the participants who showed a significant improvement in reading with an addition had reduced accommodation. Conclusions A reading addition may improve reading performance for young people with low vision and should be considered as part of a low vision assessment, particularly when accommodation is reduced.

Purpose Very poor visual acuity often cannot be measured with letter charts even at close viewing distances. The Berkeley Rudimentary Vision Test (BRVT) was developed as a simple test to extend the range of visual acuity measurement beyond the limits of letter charts by systematically simplifying the visual task and using close viewing distances to achieve large angular sizes. The test has three pairs of hinged cards, 25 cm square. One card-pair has four single tumbling E (STE) optotypes at sizes 100 M, 63 M, 40 M, and 25 M. Another card-pair has four grating acuity (GA) targets at sizes 200 M, 125 M, 80 M, and 50 M. The third card-pair has a test of white field projection (WFP) and a test of black white discrimination (BWD). As a demonstration of feasibility, a population of subjects with severe visual impairment was tested with the BRVT. Methods Adults with severe visual impairments from a wide variety of causes were recruited from three different rehabilitation programs. Vision measurements were made on 54 eyes from 37 subjects; test administration times were measured. Results For this population, letter chart visual acuity could be measured on 24 eyes. Measurements of visual acuity for STE targets were made for 18 eyes and with GA targets, for two eyes. Five eyes had WFP, and one had BWD. Four had light perception only. The median testing time with the BRVT was 2.5 min. Discussion The BRVT extends the range of visual acuity up to logMAR = 2.60 (20/8000) for STEs, to logMAR = 2.90 (20/16,000) for gratings and includes the WFP and BWD tests. Conclusions The BRVT is a simple and efficient test of spatial vision that, with 13 increments, extends the range of measurement from the limits of the letter chart up to light perception.

Purpose Contrast sensitivity is reduced in people with eye disease, and also in older adults without eye disease. In this article, we compare contrast of text presented in print and digital formats with contrast sensitivity values for a large cohort of subjects in a population-based study of older adults (the Salisbury Eye Evaluation). Methods Contrast sensitivity values were recorded for 2520 adults aged 65 to 84 years living in Salisbury, Maryland. The proportion of the sample likely to be unable to read text of different formats (electronic books, newsprint, paperback books, laser print, and LED computer monitors) was calculated using published contrast reserve levels required to perform spot reading, to read with fluency, high fluency, and under optimal conditions. Results One percent of this sample had contrast sensitivity less than that required to read newsprint fluently. Text presented on an LED computer monitor had the highest contrast. Ninety-eight percent of the sample had contrast sensitivity sufficient for high fluent reading of text (at least 160 words/min) on a monitor. However, 29.6% were still unlikely to be able to read this text with optimal fluency. Conclusions Reduced contrast of print limits text accessibility for many people in the developed world. Presenting text in a high-contrast format, such as black laser print on a white page, would increase the number of people able to access such information. Additionally, making text available in a format that can be presented on an LED computer monitor will increase access to written documents.

Purpose. Test–retest reliability of the CSV-1000 (Vector Vision) has only been reported for one adult sample. We measured the reliability of this instrument in both children and adults and also investigated the effect of changing the examiner on test–retest reliability. Methods. Test–retest log contrast sensitivity (CS) measurements were obtained for 19 young adults and 15 children by the same examiner. Test–retest log CS data were obtained from 21 young adults with different examiners. Reliability was calculated using the Bland–Altman limits of agreement, the coefficient of repeatability (COR), and the intraclass correlation coefficient. Results. All three estimates of reliability for the CSV-1000 chart are low for both children and adults using the standard recommended testing protocol. If the test–retest log CS data are obtained from the same examiner then the reliability is improved, but not significantly so. Conclusions. The reliability of the CSV-1000 is low, even if the same examiner obtains test–retest data. The data indicate that this test is unlikely to be sensitive enough to provide useful information for the clinician as is, but we suggest modifications of the procedure that may significantly increase test reliability. (Optom Vis Sci 2012;89:1172–1181)

Purpose Rarebit vision tests probe for gaps in the neuro-retinal receptive field matrix, using bright micro dots on a dark background. Previous reports have found central-vision rarebit tests useful for macular lesions. Their performance with lesions of the anterior visual pathways has not been explored. Methods Twenty-two subjects with optic nerve lesions of light to moderate severities were examined with a novel, self-contained rarebit test. Outcomes were contrasted with results of high-pass resolution perimetry and a threshold letter acuity test. Results The results of the three tests differed significantly from those of normal control subjects. There were no meaningful inter-test correlations. Analysis of receiver-operating characteristic curves revealed closely similar powers of discrimination. Mean test time for the rarebit test was 1:42 min, and for the other tests, it was approximately 5 min each. Conclusions The rarebit test appeared highly capable of detecting optic neuropathies and chiasmal lesions. Its simplicity and short test duration indicate a useful role in screening settings.

The purpose of this study was to determine how optometric practitioners modify the subjective refractive result when prescribing spectacles.Refractive data were gathered for patient visits at the School of Optometry, University of Waterloo, between January 2007 and January 2008. The entering prescription, subjective refraction, and exiting prescription were analyzed from 5001 records for patients aged ≥ 7 years.The refraction was modified to create the prescription in at least one eye in 45% of cases; specifically, 27% of cases for the sphere power, 18% for the cylinder power, 25% for the cylinder axis, and 21% for the add. Significant differences, defined as ≥ 0.50 D in sphere, cylinder, or add power or a change in axis of 15° for cylinders1 D, 10° for cylinders between 1 and ≤ 2, and 5° for cylinders2, were made in at least one eye in 17% of cases; specifically 9% of cases for the sphere power, 6% for the cylinder power, 6% for the cylinder axis, and 5% for the add. Spheres were more likely to be modified in the minus direction (weaker plus and stronger minus power) (18 vs. 11%), cylinder powers reduced (14 vs. 5%), and adds increased in power (12 vs. 8%). Modifications to create the exiting prescription were made to be closer or the same as the entering prescription 97% of the time. However, modifications were such that the entering prescription was duplicated exactly only 0.7% of the time.Optometric practitioners routinely modify the subjective refraction to create the prescription. Small modifications are common, whereas larger modifications are used more sparingly. Because there is a significant amount of clinical judgment involved in determining the refractive prescription, reliance on automated or subjective refraction alone would not be prudent.

Clinical trials to arrest, slow, prevent, or reverse blinding retinal degenerative diseases are on the horizon and are already increasing in number. Given the possible high-risk nature of some therapies, legally blind subjects with advanced eye disease are likely to be the participants in early phases of such trials; thus, these trials require reliable and well-validated measures of visual function that are particularly well suited to quantify low levels of vision.1–3 Furthermore, evaluating remaining functional vision such as visual acuity (VA) and contrast sensitivity (CS) in persons with severe vision loss is central for determining rehabilitative strategies. The ability of a person with severe vision impairment to resolve details in daily living (e.g., reading) is assessed by measures of VA, whereas the ability of a person to detect objects relative to their background (e.g., walking down steps) is measured by CS.4 Accurately evaluating visual function in these subjects requires outcome measures of VA and CS that can accommodate subjects with vision at or beyond the limits of charts established for use in clinical practice and previous clinical trials.5 The Early Treatment of Diabetic Retinopathy Study (ETDRS) chart used to measure VA and the Pelli-Robson (PR) chart used to measure CS are both standardized and validated in clinical practice, yet are suitable for monitoring VA and CS changes only in patients with VA >20/1600 (at 0.5 m) and >20/700 (at 1 m), respectively. Beyond this range, clinicians typically default to estimates such as “counting fingers” and “hand motion”; outcome measures in clinical trials require quantification, however. The range of functional deficits that accompany ocular disease may introduce other limitations for the use of letter charts. For patients with severely compromised visual fields or patients with large central or paracentral scotomas, the letters to be resolved might fall outside of the field of view or preferred retinal locus. For patients with poor acuity, resolving letters may be subject to the influence of nearby letters or high-contrast edges, and eye movements, collectively known as the “crowding effect,”6 and this effect is greater when letters are viewed in the periphery.7 The PR chart uses a single optotype size that may be at or beyond the patient’s level of VA in cases of severe vision loss, whereas it is possible for computer-based programs evaluating CS to adjust the test target size so that it is well below the patient’s threshold. Letter discrimination is dependent upon recognition of several features of a complex optotype, whereas an alternative to quantify vision beyond the range of letter charts that only requires the recognition of a single feature is a grating-based test to assess very low levels of VA.8 Discrimination of very large letter optotypes at a close test distance (e.g., at 50 cm) requires patients to effectively scan across a large area, which may be a difficult task for those with severely constricted visual fields or large central scotomas, and therefore gratings may be a better alternative. For patients with cataracts or other opacities, the use of gratings has been demonstrated to provide a better estimate of resolution.9 VA measured with gratings is less affected by optical defocus, which might be found in patients with various ocular diseases.10–12 Commercially available grating acuity tests, in particular the Teller acuity charts, have been extensively used among pediatric populations to quantify and monitor vision13 and as a vision screening test for cognitively impaired elderly in nursing homes.14 However, the use of such non-automated tests in clinical trials for low vision may be limited by interexaminer variability that could potentially influence acuity measures. The Berkeley Rudimentary Vision Test15 is a set of test cards that have been developed for subjects with more severe vision [using a single tumbling E up to 2.6 logMAR (20/8000) or gratings up to 2.9 logMAR (20/16,000) at 25 cm]. However, these tests depend on operator skill to vary the test stimuli according to patients’ responses (e.g., changing from optotype to gratings, changing or maintaining test distance, randomizing stimulus orientation order, and manual record keeping), and therefore do not lend themselves to standards of objectivity and rigorous statistics required in clinical research. Computer-based high-contrast square-wave grating tests presented on a liquid crystal display (LCD) monitor have been previously3 and are currently being used12 to quantify and monitor VA in clinical trials of retinal prostheses in patients with advanced retinitis pigmentosa (RP),2 and a grating CS test displayed on a video monitor has also been used to test a retinal degeneration patient1; however, these types of grating tests have not been independently validated outside of the clinical trials. The reliability of another newly developed VA test for patients with severe vision loss has been previously studied. The Freiburg Visual Acuity Test (FrACT) is a computerized VA test that presents Landolt C optotypes on a LCD screen using an adaptive staircase procedure and can quantify VA in the “hand motions” range between 20/2000 and 20/6060.16 However, the test-retest variability of this test in terms of a 95% confidence interval (CI) has been reported as being more variable than the ETDRS letter charts.17 The Frankfurt-Freiburg Contrast and Acuity Test is based on the FrACT and may have the potential to monitor CS in those with advanced vision loss, but this test’s capability has not yet been reported or validated. Variability of CS testing with the Frankfurt-Freiburg Contrast and Acuity Test in subjects without retinal disease has been reported to be about 1.5 to 2 times as high as with the PR letter charts.18 A computerized logMAR VA measurement system (COMPlog) was recently validated by Laidlaw et al.19 in amblyopic children and a group of ocular disease patients; however, this automated letter test only reaches a 1.68 logMAR (~20/1000) limit at 3 m and has not been validated to measure worse VA at closer test distances. Beyond this range, the program relies on scoring in terms of counting fingers or hand movements. The Basic Assessment of Light and Motion, a computerized test battery developed to evaluate temporal resolution, light perception, and localization of light and motion, was designed to measure improvements in visual function with a visual prosthesis and does not target VA or CS specifically.20 Furthermore, as VA and CS are complementary measures,8 validating tests for both VA and CS concurrently would be beneficial because ocular disease affects both measures to varying degrees. It is well known that both VA and CS are important predictors for the ability of low-vision patients to perform activities of daily living21 and mobility,22 thus validating both VA and CS tests together at more extreme ranges may be more clinically relevant. Previously described studies generally focus on validating one or the other. Clearly, a need still exists to establish reliable tests of VA and CS to monitor patients with severe vision loss. The Grating Acuity Test (GAT) and Grating Contrast Sensitivity (GCS) tests were developed to quantify varying levels of severe vision loss for use during a multicenter clinical trial of the Optobionics’ Artificial Silicon Retina for patients with RP.3 The GCS was designed to assess CS in subjects who were unable to provide meaningful results with the PR standardized test of CS, as a result of severely advanced disease resulting in reduced VA and CS. Our aim was to determine whether the grating tests may be used to follow VA and CS stability, and thus the clinical course of progressive deterioration or improvement (e.g., with effective treatment) of overall vision in legally blind subjects. To accomplish this goal, we assessed validity by comparing results with the new tests to results obtained with established VA and CS tests and the ETDRS and PR letter charts. Reliability was assessed by repeating measurements over time, both within and across sessions separated by 6 to 50 days.

Purpose To determine how high- and low-contrast visual acuities are affected by blur caused by crossed cylinder lenses. Methods Crossed cylinder lenses of power 0 (no added lens), +0.12 diopter sphere (DS)/-0.25 diopter cylinder (DC), +0.25 DS/-0.50 DC and +0.37/-0.75 DC were placed over the correcting lenses of the right eyes of eight subjects. Negative cylinder axes used were 15 to 180° in 15° step for the two higher crossed cylinders and 30 to 180° in 30° steps for the lowest crossed cylinder. Targets were single lines of letters based on the Bailey-Lovie chart. Successively smaller lines were read until the subject could not read any of the letters correctly. Two contrasts were used: high (100%) and low (10%). The screen luminance of 100 cd/m, in combination with the room lighting, gave pupil sizes of 4.5 to 6 mm. Results High-contrast visual acuities were better than low-contrast visual acuities by 0.1 to 0.2 log unit (1 to 2 chart lines) for the no added lens condition. Based on comparing the average of visual acuities for the 0.75 D crossed cylinder with the best visual acuity for a given contrast and subject, the rates of change of visual acuity per unit blur strength were similar for high contrast (0.34 ± 0.05 logarithm of the minutes of arc resolution/D) and low contrast (0.37 ± 0.09 logarithm of minutes of arc of resolution/D). There were considerable asymmetry effects, with the average loss in visual acuity across the two contrasts and the 0.50 D/0.75 D crossed cylinders doubling between the 165° and 60° negative cylinder axes. The loss of visual acuity with 0.75 D crossed cylinders was approximately twice times that occurring for defocus of the same blur strength. Conclusions Small levels of crossed cylinder blur (≤0.75 D) produces losses in visual acuity that are dependent on the cylinder axis. Crossed cylinders of 0.75 D produce losses in visual acuity that are twice those produced by defocus of the same blur strength.

Purpose To investigate the effect of secondary intraocular lens (IOL) implantation on binocular vision in patients with unilateral aphakia uncorrected consecutively for 3 years or more. Methods This study included nine patients who underwent secondary IOL implantation, but had remained in a unilateral aphakic state, without being corrected, for at least 3 consecutive years at the time of the secondary IOL implant. They also had a postoperative best-corrected visual acuity of better than 20/40 in both eyes. All patients underwent an ophthalmologic examination including best spectacle-corrected visual acuity and binocular alignment. Stereoacuity was evaluated using the Titmus Stereotest and a stereoacuity of 100 sec of arc or better was designated as "good" stereoacuity. Binocularity was determined using the polarized 4-dot test at distance and at near and the reporting of 4 dots were used to establish fusional ability. Results Four of the nine patients (44.4%) showed the highest stereoacuity of 40 sec of arc and another four patients (44.4%) showed a stereoacuity of 50 or 60 sec of arc. Only one patient showed "poor" stereoacuity of 200 sec of arc. All the patients could fuse at near and at distance on the polarized 4-dot test. Diplopia and anomalous eye movements were not found in any patient. Conclusions Secondary IOL implantation can provide good binocular vision even in patients with unilateral aphakia who had not been corrected for 3 years or more.

To compare the effects of "simulated" and "real" spherical and astigmatic defocus on visual acuity (VA).VA was determined with letter charts that were blurred by calculated spherical or astigmatic defocus (simulated defocus) or were seen through spherical or astigmatic trial lenses (real defocus). Defocus was simulated using ZEMAX and the Liou-Brennan eye model. Nine subjects participated [mean age, 27.2 ± 1.8 years; logarithm of the minimum angle of resolution (logMAR), -0.1]. Three different experiments were conducted in which VA was reduced by 20% (logMAR 0.0), 50% (logMAR 0.2), or 75% (logMAR 0.5) by either (1) imposing positive spherical defocus, (2) imposing positive and negative astigmatic defocus in three axes (0, 45, and 90°), and (3) imposing cross-cylinder defocus in the same three axes as in (2).Experiment (1): there were only minor differences in VA with simulated and real positive spherical defocus. Experiment (2): simulated astigmatic defocus reduced VA twice as much as real astigmatic defocus in all tested axes (p0.01 in all cases). Experiment (3): simulated cross-cylinder defocus reduced VA much more than real cross-cylinder defocus (p0.01 in all cases), similarly for all three tested axes.The visual system appears more tolerant against "real" spherical, astigmatic, and cross-cylinder defocus than against "simulated" blur. Possible reasons could be (1) limitations in the modeling procedures to simulate defocus, (2) higher ocular aberrations, and (3) fluctuations of accommodation. However, the two optical explanations (2) and (3) cannot account for the magnitude of the effect, and (1) was carefully analyzed. It is proposed that something may be special about the visual processing of real astigmatic and cross-cylinder defocus-because they have less effect on VA than simulations predict.

PurposeTo determine whether there are significant differences in standard clinical measures of vision, progressive addition lens (PAL)-specific vision tests, or subjective ratings and preferences between customized free-form and standard non-free-form PALs in an experienced wearing population. In addition, we aim to determine whether subjective or objective clinical outcomes depend on demographic, PAL usage, spectacle prescription, or frame fitting characteristics.MethodsIn a randomized, double-masked cross-over trial, 95 experienced wearers wore Zeiss Individual customized free-form PAL spectacles (test) and standard non-free-form PAL spectacles (control) for 1 week each. At dispensing and after 1 week of wear, subjects were tested for distance and near visual acuity under both high and low contrast; in addition, 30° off-axis visual acuity was measured using a novel apparatus, as was the horizontal extent of clear, undistorted vision at reading distance. Subjects also completed a set of questionnaires detailing their satisfaction levels, adaptation times, and preferences for test or control spectacles for different visual tasks.ResultsThe test spectacles were preferred overall and for distance, midrange, transitional and active vision, and rated higher in overall satisfaction (p = 0.006). There were no clinically important differences between test and control spectacles in standard clinical vision assessments. In the PAL-specific assessments, however, the horizontal extent of clear vision at reading distance was significantly greater with the test spectacles (p = 0.004).ConclusionsThere were statistically significant preferences for the optically customized free-form lenses over the non-free-form lenses. Subjects also reported a wider field of undistorted vision when looking through the reading zone of the test spectacles. Although standard clinical vision assessments are not sufficiently refined to detect important objective differences between the spectacle types, customization taking into account back vertex distance, segment height, pantoscopic tilt, and wrap angle can result in a superior subjective wearing experience for many PAL patients.

The aims of this study were to analyze the relationship between the performance on fine motor skills tasks and peripheral and bifoveal sensory fusion, phasic and tonic motor fusion, the level of visual acuity (VA) in the poorer seeing eye, and the interocular VA difference.Subjects aged 12 to 28 years with a range of levels of binocular vision and VA performed three tasks: Purdue pegboard (number of pegs placed in 30 s), bead threading task (with two sizes of bead to increase the difficulty, time taken to thread a fixed number of beads), and a water pouring task (accuracy and time to pour a fixed quantity into five glass cylinders). Ophthalmic measures included peripheral (Worth 4 dot) and bifoveal (4 prism diopter) sensory fusion, phasic (prism bar) and tonic (Risley rotary prism) motor fusion ranges, and monocular VA.One hundred twenty-one subjects with a mean age of 18.8 years were tested; 18.2% had a manifest strabismus. Performance on fine motor skills tasks was significantly better in subjects with sensory and motor fusion compared with those without for most tasks, with significant differences between those with and without all measures of fusion on the pegboard and bead task. Both the acuity in the poorer seeing eye (highest r value of all motor tasks = 0.43) and the interocular acuity difference were statistically significantly related to performance on the motor skill tasks.Both sensory and motor fusion and good VA in both eyes are of benefit in the performance of fine motor skills tasks, with the presence of some binocular vision being beneficial compared with no fusion on certain sensorimotor tasks. This evidence supports the need to maximize fusion and VA outcomes.