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PURPOSE: To assess test-retest repeatability of the accommodative response (AR) in children with and without amblyopia and adults using the Grand Seiko autorefractor. DESIGN: Prospective reliability assessment. METHODS: Test-retest of accommodation was obtained while participants viewed 20/150 sized letters at 33 cm using the Grand Seiko autorefractor in children 5 to

Digital eye strain encompasses a range of ocular and visual symptoms across all age groups. Recently, symptoms associated with accommodative or binocular vision stress have become a major problem, especially in young individuals. The purpose of this prospective, single-blinded study was to objectively quantify the accommodative response and visual performance of low-add soft contact lenses (CLs) in young non-presbyopic individuals.A daily disposable low-add bifocal design lens (low-add CL) was tested. It employs a centre-distance optical zone and peripheral zone with the added power of +0.50 D to support near vision. Sixteen subjects aged 20-39 years were enrolled in the study. Refractive state and accommodation were measured using an open-field autorefractor with three target vergences, namely, -0.20 D, -2.5 D, and -4.0 D. Binocular visual acuity at high (100%) and low (40%, 20%) contrast and reading ability were assessed. Monofocal soft CLs were used as controls.Accommodative response with low-add CLs was significantly smaller than those with two monofocal CL wearing conditions, i.e., at 40 cm (2.5 D of stimulus) and 25 cm (4.0 D of stimulus) (all p 0.05). The 20% contrast visual acuity at distance was significantly better with low-add CLs and second-time monofocal CLs compared to first-time monofocal CLs (all p 0.05). The reading ability was not significantly different.Quantification of accommodative response and visual performance demonstrated that using low-add CLs alleviated the accommodation under the near-vision condition, without sacrificing distance vision, in non-presbyopes.

The purpose of the present study was to assess the accommodative response and pupillary dynamics while reading passages with different text-background color combinations on an LCD screen. Twenty healthy young adults read fourteen 2-min passages designed with fourteen different color combinations between text and background, while the accommodative and pupil responses were continuously measured with a binocular open-field autorefractometer. Our results revealed that the text-background color combination modulates the accommodative and pupillary dynamics during a 2-minutes reading task. The blue-red combination induced a heightened accommodative response, whereas positive polarities were associated with more variability of the accommodative response and smaller pupil sizes. Participants reported lower perceived ratings of legibility for text-background color combination with lower luminance contrast (white-yellow). The manipulation of text-background color did not have a significant effect on reading speed. These results may have important applications in the design of digital visual interfaces.

espanolObjetivo Determinar la prevalencia de la insuficiencia acomodativa (IA) y su relacion con la edad, sexo, y errores refractivos en una poblacion universitaria de Iran. Metodos El presente estudio se realizo de forma transversal en 2017. Se realizaron pruebas optometricas a todos los estudiantes, incluyendo medicion de la agudeza visual, refraccion objetiva y subjetiva, vision binocular y pruebas de acomodacion. La amplitud de acomodacion se midio con el metodo de Donders (push-up) utilizando la regla de la RAF (Royal Air Force). La flexibilidad acomodativa monocular se midio con flippers de ±2 dioptrias. La respuesta acomodativa se evaluo mediante retinoscopia dinamica utilizando el metodo de estimacion monocular (MEM). Resultados La prevalencia de IA en la poblacion de estudiantes fue de 4,07% (95%ICI: 2,61–5,52). La tasa fue de 6,04% (95%IC: 3,58–8,5) en mujeres y 2,01% (95%IC: 0,53–3,48) en varones, y la regresion logistica reflejo un odds ratio significativamente superior de IA en mujeres (OR=3,14, 95%IC: 1,33–7,45, valor p=0,009). La prevalencia de IA fue de 2,59% (95%IC: 0,55–7,56) en el grupo de edad de 18–19 anos, y de 4,08% (95%IC: 0,09–8,07) en el grupo de 24–25 anos (valor p=0,848). La prevalencia de IA entre los individuos emetropicos, miopes e hipermetropes fue de 3,74% (95%IC: 1,88–5,61), 4,44% (95%IC: 2,07–6,81), y 5,26% (95%IC: 4,79–16,32), respectivamente (valor p=0,869). En el modelo de regresion multiple, unicamente el sexo reflejo una relacion con IA (Odds ratio=3,14 95%IC: 1,33–7,45; valor p=0,009). Conclusion La prevalencia de IA en el presente estudio es inferior a la mayoria de las tasas de prevalencia reportadas en estudios previos. En el presente estudio, sexo e IA reflejaron una fuerte asociacion, en el sentido de que la prevalencia de IA fue significativamente superior en las mujeres con respecto a los varones. EnglishPurpose To determine the prevalence of accommodative insufficiency (AI) and its relation with age, gender, and refractive errors in a college-age student population in Iran. Methods The present study was conducted cross-sectionally in 2017. All students had optometric tests including measurement of visual acuity, objective and subjective refraction, as well as binocular vision and accommodative examinations. Amplitude of accommodation was measured with the Donders’ push-up method using the Royal Air Force (RAF) rule. Monocular accommodative facility was measured with ±2.00diopter flipper lenses. The accommodative response was tested using dynamic retinoscopy with the monocular estimation method (MEM). Results The prevalence of AI in the studied population was 4.07% (95% CI: 2.61–5.52). The rate was 6.04% (95% CI: 3.58–8.50) in females and 2.01% (95% CI: 0.53–3.48) in males, and logistic regression showed a significantly higher odds of AI in females (OR=3.14, 95% CI: 1.33–7.45, p-value=0.009). The prevalence of AI was 2.59% (95% CI: 0.55–7.56) in the 18–19-year-old age group and 4.08% (95% CI: 0.09–8.07) in the 24–25-year-old group (p-value=0.848). The prevalence of AI among emmetropic, myopic, and hyperopic individuals was 3.74% (95% CI: 1.88–5.61), 4.44% (95% CI: 2.07–6.81), and 5.26% (95% CI: 4.79–16.32), respectively (p-value=0.869). In the multiple regression model, only gender showed significant relationship with AI (Odds ratio=3.14, 95% CI: 1.33–7.45; p-values=0.009). Conclusion The prevalence of AI in the present study is lower than the most prevalence rates reported in previous studies. In the present study, gender and AI showed a strong association, such that AI prevalence was significantly higher in females than males.

Firms increasingly respond to online customer reviews on public platforms to influence prospective consumers and enhance profitability. This paper highlighted the importance of semantically tailoring management responses according to the content of the reviews and examined the impact of such responses on prospective consumers and future sales. Based on a field study and an experiment, we found that an accommodative response to the product failure review and a defensive response to the ordinary negative review were effective at increasing sales and enhancing consumer purchase intentions. The effect of management response was mediated by the reduced causal attribution of negative reviews to firms. Our findings furnish meaningful implications for firm interventions on online platforms.

Some people often appear asthenopia symptoms of eye fatigue, double vision, nausea, and dizziness while viewing 3D movies. By testing the changes of accommodation function and ocular movements during watching 3D and 2D movies, the factors in visual discomfort are confirmed in this study. 20 subjects with normal visual acuity and binocular vision function view 3D and 2D movies with the same content for 30 min, and the amplitude of accommodation, binocular vergence ability, stereo-acuity, and tear break-up time of the subjects before and after viewing the films are measured. Furthermore, an open-field auto-refractor is utilized for synchronously testing the change of accommodative response while viewing 3D and 2D films, and Skalar IRIS tracking system is applied to record ocular movements through infrared positioning. In comparison with viewing 2D movies, the accommodative response and ocular movements reveal obvious changes while viewing 3D movies. The accommodation ability and binocular vergence ability obviously drop after viewing 3D movies; moreover, the stability of stereo-acuity and tear film also gets worse. The changes of such physiological factors might be the major cause of asthenopia.

The dependence of spatial frequency on accommodation has been investigated extensively. Recently, differences between myopes and emmetropes with respect to accommodative microfluctuations for high spatial frequency targets have been reported. Considering the diversity of accommodative responses (ARs) to sinusoidal gratings among subjects, this experiment was designed to analyze the contrast dependence of ARs to targets with various spatial frequencies (SFs). Here, we continuously measured ARs, microfluctuations, and pupil diameter while emmetropic and myopic adult subjects fixated on sinusoidal grating targets of various SFs under standard and near-detection threshold contrast conditions. We first evaluated the detection contrast thresholds at six SFs (2–16cpd) using a near-contrast sensitivity function test that simulated the CSV-1000 test with a tablet computer. We found no difference in contrast threshold between emmetropes and myopes. We then measured the dynamic ARs to 24 grating targets: six SFs and four contrasts (standard, detection threshold, subthreshold and suprathreshold) were recorded for 30s. Under standard contrast conditions, we observed a decrease in AR with increasing spatial frequency. Variations in pupil diameter and accommodation were the smallest at 6cpd. Both the ARs and microfluctuations were higher under near-threshold contrast conditions than under standard contrast conditions, and no variations were found across SFs under near-threshold contrast conditions. No differences in ARs or microfluctuations were found between the two refractive groups at any spatial frequency. These findings provided detailed information on accommodative behavior to spatial frequency targets under normal and high-detection demand conditions.

Purpose The aim of the present study was to compare the objective and subjective visual performance of three different soft multifocal contact lenses. Methods 10 subjects (habitual soft contact lens wearers) between the ages of 40 and 45 years participated in the study. Three different multifocal silicone hydrogel contact lenses (Acuvue Oasys, Air Optix and Biofinity) were fit within the same visit. All the lenses were fit according to the manufacturers’ recommendation using the respective fitting guide. Visual performance tests included low and high contrast distance and near visual acuity, contrast sensitivity, range of clear vision and through-focus curve. Objective visual performance tests included measurement of open field accommodative response at different defocus levels and optical aberrations at different viewing distances. Results Accommodative response was not significantly different between the three types of multifocal contact lenses at each of the accommodative stimulus levels (p > 0.05). Accommodative lag increased for higher stimulus levels for all 3 types of contact lenses. Ocular aberrations were not significantly different between these 3 contact lens designs at each of the different viewing distances (p > 0.05). In addition, optical aberrations did not significantly differ between different viewing distances for any of these lenses (p > 0.05). ANOVA revealed no significant difference in high and low contrast distance visual acuity as well as near visual acuity and contrast sensitivity function between the 3 multifocal contact lenses and spectacles (p > 0.05). Conclusions There was no statistically significant difference in accommodative response, optical aberrations or visual performance between the 3 multifocal contact lenses in early presbyopes.

This study seeks to foster a greater understanding of effective crisis communication from the internal context of organizations. The present research conducted an online experimental study of 640 full-time employees in the United States. Results through OLS multiple regression and path analysis indicated 1) employee-organization relationships (EOR) and timing strategy of self-disclosure (stealing thunder) were positively associated with the positive internal reputation and employees’ supportive behavioral intentions, 2) the positive effects of EOR on the employees’ supportive behaviors appeared differently according to whether or not stealing-thunder was used, and 3) the effects of EOR and message strategy (accommodative response) on the positive internal reputation were varied when the negative emotions (anger and anxiety) intervened.

Aniseikonia has demonstrated to deteriorate the binocular function, however its impact on the accommodative response remains unknown. The present study aimed to analyze the effects of artificially-induced aniseikonia, using afocal magnifiers, on the dynamics of the accommodative response. The magnitude and variability of the accommodative response were objectively measured in 20 young healthy subjects by a binocular open-field autorefractometer. Participants observed a static stimulus for 90 s, under seven degrees of aniseikonia (0%, 1%, 3%, 5%, 8%, 10% and 12%), and at three distances (500 cm, 40 cm and 20 cm). Complementarily, near stereoacuity, and perceived levels of fatigue and visual discomfort were assessed. The degree of induced aniseikonia was associated with the magnitude of the accommodative response (p 0.05). We also found a decline in near stereoacuity and an increment of visual symptomatology when inducing aniseikonia (p < 0.05). Our data evidenced that greater degrees of induced aniseikonia cause a heightened accommodative response. These preliminary findings may be of relevance for patients undergoing cataract or refractive surgery procedures in which aniseikonia can be induced.

The accommodative response (AR) to changes in dioptric accommodative stimulus (AS) during the latency period and onset of accommodation was investigated. Participants monocularly observed one period of a square wave in AS, with a 2-D baseline and mean, and amplitude 1 D or 2 D; the period of the square wave ranged from 0.10s to 1.00s; both increases and decreases were used for the first step in AS. At periods of 0.30s and longer, accommodation was found to respond to both levels of the stimulus. Rapid retinal monitoring appeared to be taking place for such stimuli. The amplitudes of peaks in AR did not usually depend on whether a particular level of AS occurred first or second, but for 8/40 conditions, a significant difference was found, with a stronger response when the level of AS occurred second. Null or incorrect responses were also observed in many trials, possibly linked with the natural microfluctuations of accommodation. Minimum response times to the changes in AS were observed, which increased with decreasing period of the AS. The time interval between peaks in the AR decreased with decreasing period of the AS. The findings were consistent with a parallel processing model previously proposed for saccades, where input from a later change in stimulus may enter an element of the control system when that element has finished processing an earlier change. More than one change in stimulus may therefore be passing through the multi-element control system at a time.

The time course of elongation and recovery of axial length associated with a 30min accommodative task was studied using optical low coherence reflectometry in a population of young adult myopic (n=37) and emmetropic (n=22) subjects. Ten of the 59 subjects were excluded from analysis either due to inconsistent accommodative response, or incomplete anterior biometry data. Those subjects with valid data (n=49) were found to exhibit a significant axial elongation immediately following the commencement of a 30min, 4 D accommodation task, which was sustained for the duration of the task, and was evident to a lesser extent immediately following task cessation. During the accommodation task, on average, the myopic subjects exhibited 22±34μm, and the emmetropic subjects 6±22μm of axial elongation, however the differences in axial elongation between the myopic and emmetropic subjects were not statistically significant (p=0.136). Immediately following the completion of the task, the myopic subjects still exhibited an axial elongation (mean magnitude 12±28μm), that was significantly greater (p

Greater accommodative lag and vergence deficits have been linked to attentional deficits similar to those observed in Attention Deficit Hyperactivity Disorder (ADHD). The purpose of the present study was to assess the effect of accommodative–vergence stress on a measure of sustained attention (Conners CPT) used in the diagnosis of ADHD. Twenty-seven normal non-ADHD adults completed the Conners CPT twice: wearing −2.00 D lenses and normally (without the −2.00 D lenses) in a counterbalanced order with at least 24h between the sessions. Simultaneous recording of participants’ dynamic accommodative responses was performed from the right eye using the Grand Seiko WAM-5500 auto-refractor and electroencephalographic activity (EEG) in the left prefrontal region using the Neurosky Mindset headset. The results demonstrated a significantly greater accommodative lag in the −2.00 D stress condition and a significantly poorer performance on the Conners CPT as indexed by slower reaction time, greater standard error of hit reaction time, grater response variability, poorer stimulus detectability and a greater number of perseverations. No differences were observed on measures of EEG in the theta (4–7Hz), alpha (8–12Hz), and beta (12–20Hz) bands. Moreover, when directly juxtaposed with each EEG band in multiple linear regression analyses, greater accommodative lag in the stress condition was significantly associated with a greater probability of clinical classification on the Conners CPT, and was also marginally predictive of the number of omissions recorded in the stress condition. The results demonstrated that sustained attention can be influenced by such factors as accommodative–vergence stress and suggest that bottom-up processes can contribute to and potentially exacerbate attentional problems in individuals with ADHD. The study also showed that cortical dysfunction (while sufficient) may not be a necessary condition for attentional deficits.

To measure accommodative performance as a function of refractive error in very young children.This was a prospective study of accommodation lag in multiethnic typically developing children ages 5 to 24 months. Accommodation lag was measured by means of a modified bell retinoscopy technique. Refraction was measured by cycloplegic retinoscopy, and right and left eye results were averaged. The study compared accommodative performance to cycloplegic spherical equivalent and astigmatic refractive error.Analysis of data from 189 of 203 subjects revealed that larger lags and lower gain of the accommodative response were more common in younger children, although most children of all ages accommodated well, with 95% having lags1.25 D. Larger accommodation lags were associated with greater spherical equivalent refractive error, although only with hyperopia ≥4.0 D were lags ≥1.25 D observed in a majority of children. Larger lags in the more hyperopic meridian were seen with increasing hyperopic with-the-rule astigmatism, but lag in the more hyperopic meridian varied little with the amount of myopic or mixed astigmatism.Most 5- to 24-month-old children accommodate well over a range of moderate hyperopic refractive errors, but hyperopia ≥4.0 D is rarely associated with normal accommodative performance. Hyperopic and mixed or myopic astigmatic children show different patterns of accommodation, which may explain the patterns of visual acuity deficits seen in these children.

To investigate whether or not peripheral retinal defocus contributes to the refractive development of myopia by influencing the overall accommodative function. The steady-state accommodative stimulus response curve (ASRC) and the near-work induced transient myopia (NITM) after a near visual task were compared between different visual field conditions in emmetropes (EMMs), stable myopes (SMs) and progressing myopes (PMs). Results showed that visual field had no effect on the ASRC and NITM but PMs exhibited greater NITM than EMMs and SMs. The results of this study suggest that peripheral defocus does not influence the overall accommodative system so its probable contribution to myopia development is not via the accommodative system.

This study investigates the permissible value of horizontal binocular disparity when gazing at a three-dimensional (3D) display based on ocular accommodation function. For the closely perceived image on the 3D display screen, the crossed disparity of +1.0° and of +0.5° were given and for the far image, which gave the image far away from the screen, the uncrossed disparities of −1.0° and of −0.5° were taken. The disparity was 0° when the image was displayed on the screen. When the disparity was +1.0° and the stereoscopic image had been perceived, the accommodative response became significantly larger in comparison to that at 0°. An accommodation lead was observed significantly at a disparity +1.0°. The tolerance of binocular disparity on the 3D display based on the physiological aspect of ocular accommodation is thus suggested to be less than +1.0°.

The relationships between peak velocity and amplitude of Edinger–Westphal (EW) stimulated accommodation and disaccommodation were investigated in anesthetized, middle-aged rhesus monkeys. Accommodative responses were recorded at 30 Hz with infrared photorefraction. Peak velocity of accommodation and disaccommodation increased linearly with stimulus amplitude. Peak velocities of accommodation continued to increase with stimulus amplitudes greater than required to produce the maximum response. The peak velocity of disaccommodation did not further increase with supramaximal stimulus amplitudes beyond that achieved with maximal stimulus amplitudes. Although maximum accommodative response amplitude is reduced in older rhesus monkeys, within the methodological constraints of this study, older monkeys appear to achieve accommodative and disaccommodative peak velocities similar to adolescent monkeys for the same response amplitudes.

Retinal blur and disparity are two different sensory signals known to cause a change in accommodative response. These inputs have differing neurological correlates that feed into a final common pathway. The purpose of this study was to investigate the dynamic properties of monocular blur driven accommodation and binocular disparity driven vergence-accommodation (VA) in human subjects. The results show that when response amplitudes are matched, blur accommodation and VA share similar dynamic properties.

We assessed the extent to which different accommodative functions are correlated and whether accommodative functions predict the refractive error or the progression of myopia over a 12 month period in 64 young adults (30 myopes and 34 non-myopes). The functions were: amplitude of accommodation; monocular and binocular accommodative facility (6m and 40cm); monocular and binocular accommodative response to target distance; AC/A and CA/C ratios, tonic accommodation (dark focus and pinhole), accommodative hysteresis, and nearwork-induced transient myopia. Within groups of related accommodative functions (such as facility measures or open-loop measures) measurements on individuals were generally significantly correlated, however correlations between functions from different groups were generally not significant. Although accommodative amplitude and pinhole (open loop) accommodation were significantly different in myopes than in non-myopes, these functions were unrelated to myopia progression. Facility of accommodation and accommodative lag was independent predictors of myopia progression.

The sign of an accommodative response is provided by differences in chromatic aberration between under- and over-accommodated images. We asked whether these differences enable people to judge the depth order of two stimuli in the absence of other depth cues. Two vertical edges separated by an illuminated gap were presented at random relative distances. Exposure was brief, or prolonged with fixed or changing accommodation. The gap was illuminated with tungsten light or monochromatic light. Subjects could detect image blur with brief exposure for both types of light. But they could detect depth order only in tungsten light with long exposure, with or without changes in accommodation.

Observation of the naturally-occurring accommodative response of a highly visual teleost species provides the opportunity to study its stimulus-response accuracy. A video recording system, linked to a computer digitizing program, was used to measure accommodative changes in lens position in the oscar, Astronotus ocellatus, in response to known food stimuli. The largest lens deviations occurred along an axis c. 22 deg from the pupillary plane. Consistent underaccommodation was reported for the closest of targets, a finding reminiscent of accommodative lag reported in human studies. Copyright © 1996 Elsevier Science Ltd.

Conflicting opinions exist as to whether the phasic (reflex) component alone or both the phasic and tonic (adaptive) components of the accommodation and vergence systems drive accommodative vergence and vergence accommodation crosslinks. In this study the dissociated phoria to a 2 D target was measured before and after accommodative adaptation to discriminate the two possibilities. Results showed a significant difference in the dark-focus of accommodation pre- and post- near-vision task, indicating that accommodative adaptation had occurred. No significant change occurred in dark-vergence or in the accommodative response to the 2 D target. However, a significant decrease was found in the dissociated phoria presumably because of decreased phasic accommodation and its stimulation of accommodative vergence after the adaptation. This result is consistent with a model in which the accommodative vergence crosslink is driven by phasic accommodation only.

In an earlier study (Wolfe & Owens, 1981) it was reported that humans could not accommodate to an insoluminant red-green border. However, recent masking studies (Switkes, Bradley & DeValois, 1988) have shown that, using an appropriately normalized contrast metric, contrast decrements similar to those produced by defocus are equally visible for color or luminance modulated grating patterns. We have compared accommodative responses to 1.75 c/deg gratings that consisted of either isochromatic luminance modulations or isoluminant red-green color modulations. All four observers could accommodate accurately to luminance modulated gratings over a wide range of contrasts. However, no appropriate accommodative responses were obtained even for the highest contrast color modulated gratings. These results show the changes in color contrast are ineffective as stimuli for the human accommodative response even when the changes in chromatic contrast accompanying defocus are readily perceived.

The avian accommodative response has long been suspected of having a corneal component resulting from contraction of a limbal extension of the ciliary muscle. Efforts to confirm the existence of such a mechanism have been sporadic and the results contradictory. In addition, while the accommodative mechanism of the bird eye is commonly considered to be very effective, the effect of lenticular aging is not known. The accommodative responses of excised chicken eyes of various age, were measured by photographing changes in focal effects on incident fine parallel laser beams in response to electrical stimulation of the intraocular muscles. An opening at the posterior pole of the eye enabled the beams to exit in order to facilitate measurement of refractive change. The question of a possible corneal contribution was examined by taking advantage of the fact that corneal refractive power is neutralized when the surface of the cornea is in water. Accommodation was measured with the cornea in air and in water. The results indicate that (1) there is little or no corneal accommodation and (2) accommodative ability drops off substantially with age. The results may also indicate the existence of serious inter-breed differences in chicken accommodation.

Ocular accomodation was measured in human subjects while they were rotated at 1 degree/sec about their naso-occipital axes. Sixteen normal subjects were tested with 45 complete and 27 partial revolutions. Naso-occipital rotations ipsilateral to the eye being observed caused accommodative, lens-thickening changes. This effect begin at about 14 degrees from head upright position, tended to reach a maximum by 45 degrees and usually stayed at this level until about 90 degrees. The values tended to return to control level by 180 degrees. With naso-occipital roll in the direction opposite to the eye being observed, there was little change until about 135 degrees at which point further roll was typically clear accomodation. This continued to a maximum at about 270 degrees rotation, and at about 350 degrees returned to control values. Arguments are presented relating this response to the utricles, which are approximately parallel to earth horizontal. The threshold of this response, between 3.7 and 77 cm/sec2, is similar to the threshold of linear acceleration when measured by other means.