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CCD photometric measurements were obtained from the compact binary pulsar system, PSR J1723-2837 in the visual optical band from August to October 2014. Anomalies were observed in the Light Curve (LC) and are probably a result of modulation changes during an outburst. An argument is presented that irradiation in the form of a pulsar wind may be linked to the observed event. [ABSTRACT FROM AUTHOR]

This paper proposes driver assistant system architecture based on image processing techniques. A camera is mounted on the vehicle front window to detect the road lane markings and determine the vehicle’s position with respect to the lane lines. A modified approach is proposed to accelerate the HT process in a computationally efficient manner, thereby making it suitable for real-time lane detection. The acquired image sequences are analyzed and processed by the proposed system, which automatically detects the lane lines. The experimental results show that the system works successfully for lane line detection and lane departure prediction. [ABSTRACT FROM AUTHOR]

The significance of early and sporadic reports in the 19th century of impairments of motion vision following brain damage was largely unrecognized. In the absence of satisfactory post-mortem evidence, impairments were interpreted as the consequence of a more general disturbance resulting from brain damage, the location and extent of which was unknown. Moreover, evidence that movement constituted a special visual perception and may be selectively spared was similarly dismissed. Such skepticism derived from a reluctance to acknowledge that the neural substrates of visual perception may not be confined to primary visual cortex. This view did not persist. First, it was realized that visual movement perception does not depend simply on the analysis of spatial displacements and temporal intervals, but represents a specific visual movement sensation. Second persuasive evidence for functional specialization in extrastriate cortex, and notably the discovery of cortical area V5/MT, suggested a separate region specialized for motion processing. Shortly thereafter the remarkable case of patient LM was published, providing compelling evidence for a selective and specific loss of movement vision. The case is reviewed here, along with an assessment of its contribution to visual neuroscience. [ABSTRACT FROM AUTHOR]

How do we understand the complex patterns of neural responses that underlie scene understanding? Studies of the network of brain regions held to be scene-selective-the parahippocampal/lingual region (PPA), the retrosplenial complex (RSC), and the occipital place area (TOS)-have typically focused on single visual dimensions (e.g., size), rather than the high-dimensional feature space in which scenes are likely to be neurally represented. Here we leverage well-specified artificial vision systems to explicate a more complex understanding of how scenes are encoded in this functional network. We correlated similarity matrices within three different scene-spaces arising from: (1) BOLD activity in scene-selective brain regions; (2) behavioral measured judgments of visually-perceived scene similarity; and (3) several different computer vision models. These correlations revealed: (1) models that relied on mid-and high-level scene attributes showed the highest correlations with the patterns of neural activity within the scene-selective network; (2) NEIL and SUN-the models that best accounted for the patterns obtained from PPA and TOS-were different from the GIST model that best accounted for the pattern obtained from RSC; (3) The best performing models outperformed behaviorally-measured judgments of scene similarity in accounting for neural data. One computer vision method-NEIL ("Never-Ending-Image-Learner"), which incorporates visual features learned as statistical regularities across web-scale numbers of scenes-showed significant correlations with neural activity in all three scene-selective regions and was one of the two models best able to account for variance in the PPA and TOS. We suggest that these results are a promising first step in explicating more fine-grained models of neural scene understanding, including developing a clearer picture of the division of labor among the components of the functional scene-selective brain network. [ABSTRACT FROM AUTHOR]

Purpose We examined the effect of transverse chromatic aberration ( TCA) on detection acuity for white-light interference fringes seen in Maxwellian view at various orientations and locations in the visual field. Methods A circular patch (3.5° diameter, 3.2 log Trolands) of nominally high-contrast fringes was produced on the retina by a commercial instrument (the Lotmar Visometer, Haag Streit) mounted on a gimbal for controlled positioning of the stimulus in the visual field from 0° to 35° eccentricity. Results Detection acuity for white light fringes for all meridians and eccentricities ≥15° was maximum when fringes were oriented parallel to the visual meridian line. This meridional effect disappeared when a narrow-band filter was used to eliminate TCA. The meridional effect also disappeared when the interferometric stimulator was displaced laterally to align the instrument with the eye's local achromatic axis. Conclusions Modelling confirmed that TCA is the major factor responsible for white-light meridional bias, with minor contribution arising from higher-order monochromatic aberrations and neural factors. [ABSTRACT FROM AUTHOR]

Objective : The aims of this study were to investigate the quantitative relationship between pituitary macroadenoma size and degree of visual impairment, and assess visual improvement after surgical resection of the tumor. Methods : The medical records of patients with pituitary adenoma, who had undergone trans-sphenoidal adenectomy between January 2009 and January 2011, were reviewed. Patients underwent an ocular examination and brain MRI before and after surgery. The visual impairment score (VIS) was derived by combining the scores of best-corrected visual acuity and visual field. The relationship between VIS and tumor size/tumor type/position of the optic chiasm was assessed. Results : Seventy-eight patients were included (41 male, 37 female). Thirty-two (41%) patients experienced blurred vision or visual field defect as an initial symptom. Receiver operating characteristic curve analysis showed that tumors <2.2 cm tended to cause minimal or no visual impairment. Statistical analysis showed that 1) poor preoperative vision is related to tumor size, displacement of the optic chiasm in the sagittal view on MRI and optic atrophy, and 2) poorer visual prognosis is associated with greater preoperative VIS. In multivariate analysis the only factor significantly related to VIS improvement was increasing pituitary adenoma size, which predicted decreased improvement. Conclusion : Results from this study show that pituitary adenomas larger than 2 cm cause defects in vision while adenomas 2 cm or smaller do not cause significant visual impairment. Patients with a large macroadenoma or giant adenoma should undergo surgical resection as soon as possible to prevent permanent visual loss. [ABSTRACT FROM AUTHOR]

BACKGROUND We sought to investigate the association between blood pressure levels and prevalence of acquired color vision impairment in middle-aged Japanese men. METHODS Participants underwent color vision testing, ophthalmological examination, standardized interview, physical record examination, and venous blood examination. Cardiovascular disease risk factors were determined based on blood and physical examination results and the interview. Logistic regression analysis was performed after adjusting for body mass index, systemic dyslipidemia, diabetes, cataract, glaucoma, smoking status, and drinking status. RESULTS Of 1,042 men, 872 were eligible for the study, 130 failed the Lanthony 15-hue desaturated panel (D-15 DS) diagnosed as acquired color vision impairment 15-hue, and 31 failed the Farnsworth–Munsell 100-hue test diagnosed as acquired color vision impairment 100-hue. Diastolic blood pressure was significantly correlated with both acquired color vision impairment in 100-hue patients (adjusted odds ratio (OR) for 10–mm Hg increases = 1.42; 95% confidence interval (CI) = 1.00–2.02) and acquired color vision impairment in 15-hue patients (adjusted OR for 10–mm Hg increases = 1.25; 95% CI = 1.04–1.51). The multiple-adjusted ORs for acquired color vision impairment 100-hue patients and acquired color vision impairment 15-hue patients were 7.13 (95% CI = 1.72–27.88) and 4.37 (95% CI = 1.69–11.03), respectively, for the highest blood pressure category (systolic blood pressure ≥160 and diastolic blood pressure ≥100mm Hg) compared with those for the lowest blood pressure category (systolic blood pressure <120 and diastolic blood pressure <80mm Hg). Tests for trends were significant (P < 0.05) in both analyses. CONCLUSIONS Hypertension in middle-aged men may negatively modify vision-associated neuronal function. [ABSTRACT FROM PUBLISHER]

We determined the visual efficiency and visual discomfort for users of a typical transitional space in luminous climates. The subject moves from a brighter exterior to a dimmer interior, facing an abrupt change in the level of lighting as a potential functional vision barrier, mainly for ageing people. We measured suprathreshold visual efficiency in different age groups, recognising two Landolt ring orientations and answering some visual discomfort questions. Results show: oldest group (60–67) needed more than 3 times the time required by the youngest group (25–30) to perform the task but, in terms of discomfort, there are no noticeable effects regarding the disturbance or the sensation of reduction of mobility produced by the lighting changes in the transitional space among the three different groups. [ABSTRACT FROM PUBLISHER]

Though several electronic assistive devices have been developed for the visually impaired in the past few decades, however, relatively few solutions have been devised to aid them in recognizing generic objects in their environment, particularly indoors. Nevertheless, research in this area is gaining momentum. Among the various technologies being utilized for this purpose, computer vision based solutions are emerging as one of the most promising options mainly due to their affordability and accessibility. This paper provides an overview of the various technologies that have been developed in recent years to assist the visually impaired in recognizing generic objects in an indoors environment with a focus on approaches based on computer vision. It aims to introduce researchers to the latest trends in this area as well as to serve as a resource for developers who wish to incorporate such solutions into their own work. [ABSTRACT FROM AUTHOR]

An achromatic element eliminating only longitudinal chromatic aberration (LCA) while maintaining transverse chromatic aberration (TCA) is established for the eye model, which involves the angle formed by the visual and optical axis. To investigate the impacts of higher-order aberrations on vision, the actual data of higher-order aberrations of human eyes with three typical levels are introduced into the eye model along visual axis. Moreover, three kinds of individual eye models are established to investigate the impacts of higher-order aberrations, chromatic aberration (LCA+TCA), LCA and TCA on vision under the photopic condition, respectively. Results show that for most human eyes, the impact of chromatic aberration on vision is much stronger than that of higher-order aberrations, and the impact of LCA in chromatic aberration dominates. The impact of TCA is approximately equal to that of normal level higher-order aberrations and it can be ignored when LCA exists. [ABSTRACT FROM AUTHOR]

The paper describes a new elosed-form solution for the lost-in-space visual navigation problem. Focal plane images of several known beacons are used to determine both position and attitude of a sensor equipped with position-sensing diodes. A preliminary set of possible solutions is obtained without any initial guesses using any three beacons. These solutions employ a closed-form method for finding sensor-to-beacon distances based on their lines of sight. Instead of providing these solutions in terms of polynomial roots, the paper for the first time derives these solutions explicitly and includes a complete error analysis. Using additional beacons, the possible three-beacon solutions are refined, extraneous solutions are discarded, and the best solution is identified via the Gauss-Newton method. The paper also includes numerical examples and a statistical validation of the proposed method. [ABSTRACT FROM AUTHOR]

We present in this paper the quantification of the geometrical features of the anterior segment of the eye using Anterior Segment Optical Coherence Tomography (AS-OCT). This quantification was achieved by following our own developed methodology including the device development and their distortion calibration (Fan and refraction) for 3-D imaging, and automatic analysis tools as well. The stastistical comparison of the corrected topographies of the anterior cornea with topographies from state-of-the art clinical topography systems represents a valuable contribution toward the development "All-OCT-based" topographic systems. In addition, we first reported topographies of the crystalline lens in vivo, which is a promising tool to investigate the lens optical properties, the contribution of the lens to the overall retinal image quality, and understanding the change of the physical properties of the lens with accommodation and aging. Furthermore, our quantitative ASOCT allowed the analysis of the keratoconic cornea and the changes produced by Intra Corneal Ring Segment (ICRS) treatment, as well as monitoring of the ICRS 3-D location. Finally, OCT-based biometry we present in this paper is a promising tool to investigate the changes after cataract surgery; the contribution of the (Intra Ocular Lens) IOL location and tilt to the overall retinal image quality, and in the design of new IOLs. [ABSTRACT FROM AUTHOR]

Estimating the pose of a plane given a set of point correspondences is a core problem in computer vision with many applications including Augmented Reality (AR), camera calibration and 3D scene reconstruction and interpretation. Despite much progress over recent years there is still the need for a more efficient and more accurate solution, particularly in mobile applications where the run-time budget is critical. We present a new analytic solution to the problem which is far faster than current methods based on solving Pose from $$n$$ Points (PnP) and is in most cases more accurate. Our approach involves a new way to exploit redundancy in the homography coefficients. This uses the fact that when the homography is noisy it will estimate the true transform between the model plane and the image better at some regions on the plane than at others. Our method is based on locating a point where the transform is best estimated, and using only the local transformation at that point to constrain pose. This involves solving pose with a local non-redundant 1st-order PDE. We call this framework Infinitesimal Plane-based Pose Estimation (IPPE), because one can think of it as solving pose using the transform about an infinitesimally small region on the surface. We show experimentally that IPPE leads to very accurate pose estimates. Because IPPE is analytic it is both extremely fast and allows us to fully characterise the method in terms of degeneracies, number of returned solutions, and the geometric relationship of these solutions. This characterisation is not possible with state-of-the-art PnP methods. [ABSTRACT FROM AUTHOR]

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The following article presents researches aimed at the evaluation of precision in determining a ship's position through comparing a omnidirectional map image to a real vision image of the coast line. The first part establishes the thesis and preparatory forms in conducting the research. It also presents designed and built equipment including a research tool software. A system equipped with a spherical catadioptric camera that aids data collection on board ship designated to processing and analyzing data collected on board in connection with the spherical images of an electronic navigational chart with a software module. The second part explains procedures followed in conducting the research. The foreword note explains the procedure in data collection aboard a ship maneuvering in the port after which the algorithm for position placement and precise parametrical count was presented. The concluding part shows analyses of obtained research result. It bears a performance on the evaluation of precision at determining position. As a measure, an average error value and distance fluctuation of obtained position from referential position. As our conclusion, primary agents having rudimentary influence on the quality of correlating spherical map image to coastline visual image were characterized. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To evaluate the power profile of multifocal contact lenses (CLs) using a new technology based on quantitative deflectometry. Methods: The Nimo TR1504 was used to analyze the power distribution of multifocal CLs. The CLs under study were: Air Optix Aqua Multifocal Low, Medium and High Addition and Focus Progressives. Three lenses of each model were considered. Results: All multifocal CLs showed a power profile characterized by a change toward more positive power values when aperture sizes become smaller. The near refractive addition of the lenses under study was +2.61D, +1.44D, +1.30D and +0.30D for the Focus Progressives, the Air Optix Aqua Multifocal High, Medium Add and Low Add, respectively. The refractive power of the Focus Progressives did not reach the value of the nominal distance power until a radial distance of 0.9mm from the center of the lens. For the Air Optix Aqua Multifocal Low Add the distance nominal power was reached at a radial distance of 1.5mm from the center of the lens, whereas this occurred at a distance of 1.8mm for the Air Optix Aqua Multifocal Medium and High Add. Conclusion: The relation between the pupil diameter of the patients and the power profile of these CLs has a crucial implication on the final distance correction and near addition that these lenses provide to patients. Practitioners should know the power profile of these CLs and measure the pupil diameter of each patient in different situations in order to carry out a customized fitting. [Copyright &y& Elsevier]

To achieve the better performance of image quality assessment, this paper develops an information-based scheme. First, visual maps that contain visual information are extracted by non-tensor product wavelet filter banks at different scales. Subsequently, to model visual difference (VD) caused by image degradations, the variation of information entropy between distorted and reference images is employed. Then the final visual quality is calculated with the VDs at each scale. In experiments, evaluation results show that it performs very well in terms of high accuracy of image quality measurement as well as low data rate. [ABSTRACT FROM AUTHOR]

We compared monocular and binocular absolute thresholds of dark adaptation in two separate study populations. Eighteen healthy individuals (Group A) and 13 patients with chronic respiratory insufficiency (Group B) were examined three times each by computerised dark adaptometry with simultaneous but separate recordings from each eye and binocularly. The respiratory patients received oxygen supplement at visits 1 and 3. In Group A, at all three visits, binocular dark adaptation was significantly more sensitive (40.5%) than monocular dark adaptation with either eye. In Group B, at visits 1 and 3, binocular dark adaptation was also significantly more sensitive than monocular dark adaptation (40.5% higher than the right and 47% higher than the left eye). However, in Group B, at visit 2 without oxygen treatment, no significant differences were observed between monocular and binocular sensitivities. Binocular dark vision was superior to monocular dark vision in healthy individuals and in patients with respiratory insufficiency that were provided oxygen supplementation. Furthermore, deficit in oxygen seems to affect binocular summation, perhaps by impaired enhancement in the central nervous system. [ABSTRACT FROM AUTHOR]

Purpose: Both the plusoptiX photoscreener photoscreener and the SureSight autorefractor can be used to objectively screen for amblyogenic risk factors in children. We compare the plusoptiX and the SureSight to a pediatric ophthalmology examination on a single cohort of children. Methods: We performed a retrospective medical records review of 90 children. Each patient was screened with both the PlusoptiX A09 and SureSight devices on the same day as part of a comprehensive pediatric ophthalmic examination. The ages of the patients ranged from <1 to 17 years. All patients had a cycloplegic refraction on the day of their exam, or within the previous 6 months. Results: Of the children reviewed, 71% had amblyopia risk factors. The plusoptiX demonstrated a sensitivity of 98% and a specificity of 88%. The SureSight demonstrated a sensitivity of 95% and a specificity of 65% utilizing the manufacturer's criteria. Conclusion: The SureSight and plusoptiX were both found to be reliable objective vision screening devices, though the plusoptiX did have a higher sensitivity and specificity than the SureSight using the manufacturer's referral criteria. Using the Vision In Preschoolers Study (VIPS) referral criteria, the specificity of the SureSight improved but the sensitivity was reduced. [ABSTRACT FROM AUTHOR]

Does our perceptual awareness consist of a continuous stream, or a discrete sequence of perceptual cycles, possibly associated with the rhythmic structure of brain activity? This has been a long-standing question in neuroscience. We review recent psychophysical and electrophysiological studies indicating that part of our visual awareness proceeds in approximately 7-13 Hz cycles rather than continuously. On the other hand, experimental attempts at applying similar tools to demonstrate the discreteness of auditory awareness have been largely unsuccessful. We argue and demonstrate experimentally that visual and auditory perception are not equally affected by temporal subsampling of their respective input streams: video sequences remain intelligible at sampling rates of two to three frames per second, whereas audio inputs lose their fine temporal structure, and thus all significance, below 20-30 samples per second. This does not mean, however, that our auditory perception must proceed continuously. Instead, we propose that audition could still involve perceptual cycles, but the periodic sampling should happen only after the stage of auditory feature extraction. In addition, although visual perceptual cycles can follow one another at a spontaneous pace largely independent of the visual input, auditory cycles may need to sample the input stream more flexibly, by adapting to the temporal structure of the auditory inputs. [ABSTRACT FROM AUTHOR]

Optical flow estimation is a fundamental task of many computer vision applications. In this paper, we propose a fast simple algorithm to compute optical flow based on the 3-D gradient in video sequences. Although the algorithm does not provide highly accurate results, it is computationally simple and fast, and the output is applicable for many applications. The basic idea is that points will form trajectories in video sequences, and the trajectory between two frames of each point is approximated as a straight line, which is the tangent of the trajectory in our algorithm. Therefore, the optical flow of each point is the projecting line of the straight line, which represents its trajectory, in the image plane. Experimental results show that the proposed algorithm is efficient and effective, and is of satisfying accuracy on angle. It is able to provide effective optical flow results for real-time applications. [ABSTRACT FROM PUBLISHER]

Highlights: [•] We asked subjects to compare the speed of moving gratings. [•] Perceived speed increases with visual contrast. [•] Whether this bias increases or decreases with speed depends on contrast levels. [•] A Bayesian model is used to extract individuals’ speed prior. [•] Combined Bayesian+ratio model describes data better than either model alone. [ABSTRACT FROM AUTHOR]

GLO:JRF/01may21:opo12808-fig-0005.jpg PHOTO (COLOR): . gl B Jos J. Rozema b received a Master degree in Physics at the University of Antwerp (Belgium), where he also completed a PhD in Physics (2004) and a PhD in Medical Sciences (2017). Jason is an Associate Topical Editor for Optometry & Vision Science, as well as a Fellow of the American Academy of Optometry and the Association for Research in Vision and Ophthalmology. Dr. Hassan received both her optometry degree and PhD from the Queensland University of Technology in Brisbane, Australia and is currently an Associate Professor at the Indiana University School of Optometry in Bloomington, Indiana. [Extracted from the article]

In this paper we describe the additive and multiplicative decomposition of refraction matrices with respect to a dihedral basis and show the effectiveness of that basis in developing new statistical summaries of refraction data. We also show that under certain projective restrictions the refraction matrices are homeomorphic to an open solid torus and discuss the many potential data-analytic consequences of that representation. A local analysis based on a class of Möbius transformations is introduced leading to a set of new summary statistics of potential use in comparative and correlational studies of refraction data. [ABSTRACT FROM PUBLISHER]

Purpose: To compare the visual outcomes, reading performance, and quality of life (QoL) of working-age cataractous patients bilaterally implanted with 3 different diffractive multifocal intraocular lenses (MIOLs). Design: Two-center, randomized, prospective, double-masked study. Participants: Sixty-three consecutive patients (126 eyes) seen at Ophthalmology Section, Palermo and Florence University, Italy, randomized to receive the ReSTOR SN6AD3 (Alcon Laboratories, Inc, Irvine, CA) (20 patients, group A), ReSTOR SN6AD1 (Alcon Laboratories, Inc) (21 patients, group B), or TECNIS ZMA00 (Abbott Medical Optics, Santa Ana, CA) (22 patients, group C) MIOL. Intervention: Phacoemulsification. Main Outcome Measures: One-year follow-up differences among the 3 MIOL groups in visual acuity, reading performance by MNREAD (Minnesota Laboratory for Low-Vision Research, University of Minnesota, Minneapolis, MN) reading acuity (RA), critical print size (CPS), and maximum reading speed (MRS) under mesopic and photopic conditions. Secondary Outcome Measures: Photopic and mesopic contrast sensitivity (CS) by Pelli–Robson test and patient satisfaction by National Eye Institute Refractive Error Quality of Life Instrument-42 (NEI RQL-42) questionnaire. Results: Mean photopic uncorrected near visual acuity (UNVA), distance-corrected near visual acuity (DCNVA), and corrected near visual acuity (CNVA) did not differ among groups, with a preferred reading distance greater in group B (P < 0.0005). Photopic distance-corrected intermediate visual acuity (DCIVA) was best in group B (P = 0.001) and better in group C than in group A. Mesopic UNVA and DCNVA were worse in groups A and B compared with group C (P < 0.0005 in both cases), with better DCNVA in group B than in group A (P = 0.031). Mesopic uncorrected intermediate visual acuity (UIVA) and DCIVA were worst in group A, with better results in group C (P < 0.0005 and P = 0.001, respectively). Mesopic MNREAD RA was better in group C (P = 0.02), and mesopic MRS was higher in groups B and C than in group A (P = 0.002). The QoL scores by the NEI RQL-42 test exhibited no differences among groups in 9 over 13 scales. “Near vision” (P = 0.005), “symptoms” (P = 0.001), and “satisfaction with correction” scale scores (P = 0.030) were lowest in group A, and “appearance” scale score was lowest in group B (P = 0.045). Conclusions: Newer-generation aspheric diffractive MIOLs, especially low-add hybrid apodized or full diffractive, are highly suited for working-age cataractous patients in terms of visual outcomes, reading performance, and QoL. Intrinsic optical differences, such as optimization for computer or dim-light working, or night driving, could be useful tools to customize the IOL in each single case. [Copyright &y& Elsevier]

Highlights: [•] A uroflowmeter based on image processing technology is feasible. [•] Device accuracy (±1.4mL/s) is comparable to those used clinically. [•] Device accuracy exceeds ICS recommendations (2.5mL/s). [•] The device consists of few parts and may be assembled for a few hundred dollars. [ABSTRACT FROM AUTHOR]

Because of their unique visual optic and electronic properties, substituted quinones are commonly used as dyes and pigments; nevertheless, a theoretic background of relationship between the structures and optical properties of such compounds seems to be still undeveloped. Two crystalline forms of 2-methoxynaphth-1-yl-naphthoquinone (MNQ) have been synthesized and characterized by means X-ray, NMR, UV-VIS, as well as, MS spectroscopy. The interpretation of intriguing optical properties of two crystalline forms of MNQ, based on detailed spectral and structural characterization, as well as, DFT and MP2 computations clearly connects the conformation of the molecules with their optical and electronic properties. Thus, flatter conformation, stabilized by crystal net force, favours the intense electron density transition from auxochrome to chromophore moiety (which corresponds excitation from HOMO to LUMO), as well as, favours the π-stacking interaction, that eventually results in colour enhancement. At the same time, small molecules of solvents included into the crystal net allow molecules of arylnaphthoquinones to adopt less rigid conformation what has a dramatic optical outcome. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Johannes Vermeer of Delft [1632-1675] was one of the greatest Masters of the Dutch Golden Age who was intensely preoccupied with the behavior of light and other optical effects and was entitled "The Master of Light". He fastidiously attended to the subtleties of visual expression through geometry, composition, and precise mastery of the rules of perspective. It has been our impression that some visual similarity does exist between neuroendoscopic images and some of Vermeer's paintings. Such a relation could be explained by the fact that optical devices are utilized in producing both types of display. Methods: We reviewed the pertinent medical and art literature, observed some video clips of our endoscopy cases, and inspected digital high resolution images of Vermeer's paintings in order to elaborate on shared optical phenomena between neuroendoscopic views and Vermeer's paintings. Results: Specific optical phenomena are indeed shared by Johannes Vermeer's works and neuroendoscopic vision, namely light and color effects as well as the rules of perspective. Conclusion: From the physical point of view, the possibility that a camera obscura inspired Vermeer's artistic creation makes the existence of a visual link between his paintings and the endoscopic views of the intracranial cavity comprehensible. [ABSTRACT FROM AUTHOR]

Despite extensive evidence of the possible interactions between multisensory signals, it remains unclear at what level of sensory processing these interactions take place. When two identical auditory beeps (inducers) are presented in quick succession accompanied by a single visual flash, observers often report seeing two visual flashes, rather than the physical one - the double flash illusion. This compelling illusion has often been considered to reflect direct interactions between neural activations in different primary sensory cortices. Against this simple account, here we show that by simply changing the inducer signals between featurally distinct signals (e.g. high- and low-pitch beeps) the illusory double flash is abolished. This result suggests that a critical component underlying the illusion is perceptual grouping of the inducer signals, consistent with the notion that multisensory combination is preceded by determination of whether the relevant signals share a common source of origin. [ABSTRACT FROM AUTHOR]

Purpose: To compare the efficacy, predictability, and safety outcomes of 2 femtosecond laser platforms for flap creation during laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism. Setting: Singapore National Eye Centre, Singapore. Design: Retrospective case review. Methods: In this single-center multisurgeon study, patients had LASIK with flaps created using a Visumax 500 kHz or Intralase 60 kHz femtosecond laser system. Ablation was performed with the Wavelight Allegretto Eye-Q 400 Hz excimer laser in all patients. Preoperative and 3-month postoperative manifest refraction, attempted treatment spherical equivalent (SE), visual acuity, and complications were compared. Results: The 500 kHz femtosecond laser group comprised 381 patients (381 eyes) and the 60 kHz femtosecond laser group, 362 patients (362 eyes). Three months postoperatively, the uncorrected distance visual acuity was 20/40 or better in 99.1% of eyes in the 60 kHz laser group and 99.4% of eyes in the 500 kHz laser group (P=.678). Regarding predictability, 98.6% of eyes and 97.4% of eyes, respectively, were within ±1.0 diopter of the attempted SE correction postoperatively (P=.228). The safety index was similar in the 60 kHz laser group and the 500 kHz laser group (mean 1.06 ± 0.16 [SD] versus 1.05 ± 0.14) (P=.321). Conclusion: The safety, predictability, and efficacy profiles of the 500 kHz femtosecond platform for LASIK were excellent and comparable to those of the 60 kHz platform. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [ABSTRACT FROM AUTHOR]

Saccade endpoints are most frequently characterized by an undershooting bias. Notably, however, some evidence suggests that saccades can be made to systematically under- or overshoot a target based on the magnitude of the eccentricities within a given block of trials (i.e., the oculomotor range effect hypothesis). To address that issue, participants completed stimulus-driven saccades in separate blocks of trials (i.e., proximal vs. distal) that entailed an equal number of targets but differed with respect to the magnitude of their eccentricities. In the proximal block, target eccentricities were 3.0°, 5.5°, 8.0°, 10.5° and 13.0°, whereas in the distal block target eccentricities were 10.5°, 13.0°, 15.5°, 18.0° and 20.5°. If the range effect represents a tenable hypothesis, then the magnitude of target eccentricities within each block should selectively influence saccade endpoint bias. More specifically, the eccentricities common to the proximal and distal blocks (i.e., 10.5° and 13.0°) should elicit a systematic under- and overshooting bias, respectively. Results for the proximal and distal blocks showed a reliable undershooting bias across target eccentricities, and a direct comparison of the common eccentricities indicated that the undershooting bias was not modulated between blocks. Moreover, our results show that the presence of online target vision did not influence the undershooting bias. Thus, the present findings provide no support for an oculomotor range effect; rather, results evince the mediation of saccades via a control strategy that minimizes movement time and/or the energy requirements of the response. [ABSTRACT FROM AUTHOR]

Earlier work examining susceptibility to visual illusions in autism has reported discrepant findings. Some of this research suggests that global processing is affected in autism while some of this research suggests otherwise. The discrepancies may relate to compliance issues and differences in population samples in terms of symptom severity, cognitive ability, and co-morbid disorders. Equally important, most of this work tended to treat global processing as if it were a singular construct, invoking similar cognitive operations across different visual illusions. We argue that this is not a fair assumption to make given the extensive research that has classified visual illusions on the basis of their cognitive demands. With this in mind, and to overcome the many caveats associated with examining a heterogeneous disorder such as autism directly, we examined how susceptibility to various illusions relates differently to people's scores on the Autism Spectrum Quotient (AQ) questionnaire. We found that susceptibility to the Müller-Lyer but not to the Ebbinghaus and Ponzo illusions decreased as a function of AQ and that the relationship between AQ and susceptibility to the Müller-Lyer illusion was different from those between AQ and susceptibility to the Ebbinghaus and Ponzo illusions. Our findings confirm that the cognitive operations underlying global processing in the Müller-Lyer illusion are different from the other illusions and, more importantly, reveal that they might be affected in autism. Future brain mapping studies could provide additional insight into the neural underpinnings of how global processing might and might not be affected in autism. [ABSTRACT FROM AUTHOR]

The basic optical illusions as: stroboscopic effect, bird in a cage phenomenon, effect of circulating pendulum, permanence of vision effect, waterfall effect, depth of seeing phenomenon and Benhams effect are described and its examples are given. The mentioned illusions are also explained and experimental method its demonstration are presented. Oc-currence and significance this illusions in every day life and modern technology are also discussed. [ABSTRACT FROM AUTHOR]

Objective: To study the anatomic and visual outcomes of descemetopexy in Descemet's membrane detachment (DMD) after cataract surgery. Design: Retrospective case series. Participants: Clinical notes of 60 patients who underwent DMD after cataract surgery between 2007 and 2011. Methods: Descemetopexy was performed with air or 14% isoexpansile perfluoropropane (C3F8). Main Outcome Measures: Anatomical (reattachment rates) and functional results (best-corrected visual acuity) were studied. Secondary outcome measures were assessment of surgical complications and association of various factors with final visual outcome. Results: The mean age of the patients was 64.3±8.3 years, and the male:female ratio was 21:39. At 1 month, the mean logarithm of the minimum angle of resolution (logMAR) interval visual acuity (IVA) improved from 1,27±0.8 to 0.42±0.49 (P < 0.001). Five patients (8.3%) obtained 20/20 vision, and 37 of 60 patients (61.6%) achieved IVA of >20/40. Ninety-five percent (57/60) of patients had successful reattachment of the Descemet's membrane (DM) after the intervention. Multiple linear regression analysis showed that patients with a cataract score of 5 (estimate = 0.38; P=0.014), with a cataract score of 4 with compromised visibility due to a corneal opacity (estimate = 0.45; P=0.039), and prolonged duration between cataract surgery and descemetopexy (estimate = 0.012; P=0.007) were associated with a significantly poorer final visual outcome. No association of final visual outcome was observed with age; sex; eye treated; cataract scores 2, 3, and 4; preoperative visual acuity; and involvement of the visual axis (P > 0.5). The eyes in which air was used for descemetopexy (estimate = -0.2; P=0.009) had statistically significantly better final visual outcomes. Three patients (5%) had treatment failures and required subsequent endothelial transplantation. Pupillary block was observed in the early postoperative period in 7 patients (11.66%) in whom C3F8 had been used and was not seen with air (P=0.02). Conclusions: This study suggests that DMD after cataract surgery can be treated effectively and good visual outcomes can be expected if the patient is treated in time with anterior chamber injection of gas. Air has advantages of better efficacy than C3F8 without the risk of pupillary block and thus should be preferred. [ABSTRACT FROM AUTHOR]

Purpose To understand how primary and secondary spherical aberrations affect focusing of the retinal image and the measurement of refractive state in the accommodating eye. Methods A computational eye model was constructed from published anatomical dimensions of the eye's refractive elements for a range of accommodative states. Two strategies for controlling accommodation were implemented, one in which paraxial rays are always perfectly focused and the other in which paraxial accommodative lag grew larger as target vergence increased. Multiple configurations of the model were achieved by selecting various combinations of pupil size and aberration structure. Refractive state was defined as optimum target vergence for maximizing retinal image quality according to several scalar metrics. Results When accommodation optimally focuses paraxial rays, retinal image quality is sub-optimal for metrics of image quality sensitive to non-paraxial rays. This loss of image quality can be recovered by optimizing target vergence computationally, which indicates the presence of real accommodative error according to the non-paraxial metric even though the eye is accurately focused paraxially. However, such errors are spurious if non-paraxial refractive state is misinterpreted as paraxial refractive state. Accommodative errors may indicate lag or lead, but in general the slope of the stimulus-response function is less than 1 for non-paraxial measures of image quality. These results depend strongly on pupil size and its variation due to accommodative miosis. Conclusions spurious accommodative errors can appear when the eye focuses the retinal image optimally according to one metric of image quality (e.g. paraxial) while ocular refractive state is measured by another (e.g. non-paraxial). Spurious errors are small compared to real accommodative lag for small, photopic pupils but can be of the same order of magnitude as real lag for large, mesopic pupils. [ABSTRACT FROM AUTHOR]

The aim of this study is the treatment done in a modern vision of the theoretical and practical Lapus Country phytosociologically and ecologically. The scientific novelty of the investigation was to achieve cenotaxonomy. The region stockings under study regard field identification and description of several plant associations in the study area. Also, drafting tables and graphs comparative analytic characterization allowed cenotaxonomic and ecological plant associations. A useful tool in the analysis of ecological categories of plants are values corresponding indicator and the main ecological factors that are found in both floristic list totals 1,212 plant tax belonging cormophyte and the analytical tables of plant associations described in the study. [ABSTRACT FROM AUTHOR]

We present a hybrid configuration of joint transform correlator (JTC) and joint fractional transform correlator (JFTC) for encryption purpose. The original input is encoded in the joint fractional power spectrum distribution of JFTC. In our experimental arrangement, an additional random phase mask (master key) is holographically generated beforehand by a Mach-Zehnder interferometer with a JTC as the object arm. The fractional order of JFTC, together with the master key, can remarkably strengthen the safety level of encryption. Different from many previous digital-holography-based encryption schemes, the stability and alignment requirement for our system is not high, since the interferometric operation is only performed in the generation procedure of the master key. The advantages and feasibility of the proposed scheme have been verified by the experimental results. By combining with a multiplex technique, an application for multiple images encryption using the system is also given a detailed description. [ABSTRACT FROM AUTHOR]

Objectives: A well-balanced curriculum is critical for ensuring that students graduate with the necessary skills. There is growing interest in evaluating the functional value of non-clinical courses compared to clinical courses. The purpose of this study was to evaluate the views of optometry and vision science professionals on the utility and relevance of optics-based courses., Methods: A web-based survey was designed to assess the perceived significance of the optics-based courses. All respondents were alumni of two universities in Jordan that offer an undergraduate degree in optometry. The survey included questions about the professional relevance of optics courses. Respondents were asked to rate several statements related to the relevance and importance of optics courses in current optometry practice on a 5-point Likert scale., Results: In total, 205 respondents completed the online survey. There were 161 (78.5%) women and 44 (21.5%) men, with an average age of 28.76 (± 4.86) years. Overall, respondents rated the perceived usefulness of optics courses for their careers with a mean collective value of 20.78 out of a possible 30 points. Female alumni perceived the courses as significantly more useful in their workplace than male alumni did ( p  = .020). Optometrists in different age groups perceived usefulness differently ( p  = .001). Alumni who preferred to learn these courses on-site and by hybrid methods perceived optics courses as significantly more useful than those who preferred to learn online ( p  = .006 and p  < .001, respectively)., Conclusions: The perceived importance of optics-based courses varied according to several factors. However, in general, these courses were deemed helpful in terms of curricular content and practical relevance to practice, regardless of specialisation or the workplace.Key messagesIn terms of the value offered to the professional competencies that an optometrist needs, the practical utility of optics courses in optometry curriculums is contested.Optometrists' perceptions of optics courses were examined using a cross-sectional survey.Respondents rated the perceived usefulness of optics courses for their career, with a mean collective value of 20.78 out 30 points.The highest percentage of respondents in this study expressed their preference for the face-to-face learning method rather than the hybrid method.Male optometrists perceived learning optics courses as significantly less helpful than female optometrists.

Two optical methods for visualizing physical processes that occur in an evaporating liquid drop on a horizontal substrate are considered: the method of frustrated total internal reflection and the interference method. The experimental setup that allows implementation of these methods is described. The obtained experimental data and the results of their processing are presented. [ABSTRACT FROM AUTHOR]

Abstract: Classically, diffraction theory sets a boundary for the resolving capacity of optical instruments. Yet some visual thresholds have values much better than the traditional resolution limit. Recent developments in superresolution, an area of optical physics and engineering with claims of transcending the stated resolution limits of optical instruments, are reviewed and their possible relevance to visual spatial processing and to the exploration of the eye''s structure are assessed. In optical or diffractive superresolution the transmitted spatial-frequency band is not so much extended as either multiplexed with or displaced into regions that are usually beyond reach, with no overall gain in information transfer because prior knowledge is used to make inferences of possible object structure from the image. The Uncertainty Principle for photon position and momentum is never disobeyed. The study of the neural substrate of visual hyperacuity does, however, overlap that of “geometrical superresolution,” in which techniques are used for transcending limits imposed by the receptor lattice in analyzing fine image structure. [Copyright &y& Elsevier]