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Brief periods of monocular deprivation significantly modify binocular visual processing. For example, patching one eye for a few hours alters the inter-ocular balance, with the previously patched eye becoming dominant once the patch is removed (Lunghi, Burr, & Morrone, 2011; Lunghi, Burr, & Morrone, 2013). However, the contribution of higher-level visual processing to this phenomenon is still unclear. Here, we compared changes in sensory eye dominance produced by three types of monocular manipulations in adult participants with normal binocular vision. One eye was covered for 150 minutes using either an opaque patch, a diffusing lens, or a prism that inverted the image. All three manipulations altered dominance duration and predominance during binocular rivalry (BR) in favour of the treated eye and the time courses of the changes were similar. These results indicate that modifications of luminance or contrast are not strictly necessary to drive shifts in eye dominance, as both were unaltered in the prism condition. Next, we found that shifts in eye dominance were dependent on attentional demands during the monocular treatment period, providing support for the role of attentional eye selection in modulating eye dominance. Finally, we found relatively rapid build-up of the ocular dominance shift after the onset of monocular treatment. Taken together, our results suggest that modifications to monocular input alter inter-ocular balance via selective attentional mechanisms that bias output towards the deprived eye. Eye-based attention may play an important role in conditions where normal input to one eye is disrupted, such as childhood amblyopia.

Most humans do not only have a preferred hand to use in different situations, they also exhibit a clear preference when it comes to eye usage. Few studies have assessed whether different tests of eye preference give congruent or incongruent results, and furthermore, there are conflicting findings on whether eye preference correlates with eye dominance, visual acuity, and handedness. The present study assessed whether these variables correlate, alongside factors such as age and sex. A total of 79 subjects, 45 males and 34 females, were tested. A microscope, telescope, photo camera, and caleidoscope were used to assess eye preference, the Dolman test was used to assess eye dominance, the Edinburgh Handedness Inventory was filled in to assess handedness, and visual acuity was measured using a Snellen chart. Care was taken to include subjects of various ages and both sexes. Descriptive statistics show that most subjects were right-handed, had a right-eye preference and were consistent across the four eye preference tasks, and had a dominant right eye. Significant correlations were found between visual acuity and handedness, as well as eye preference and eye dominance.

Animals, from invertebrates to humans, stabilize the panoramic optic flow through compensatory movements of the eyes, the head or the whole body, a behavior known as optomotor response (OR). The same optic flow moved clockwise or anticlockwise elicits equivalent compensatory right or left turning movements, respectively. However, if stimulated monocularly, many animals show a unique effective direction of motion, i.e., a unidirectional OR. This phenomenon has been reported in various species from mammals to birds, reptiles, and amphibious, but among invertebrates, it has only been tested in flies, where the directional sensitivity is opposite to that found in vertebrates. Although OR has been extensively investigated in crabs, directional sensitivity has never been analyzed. Here, we present results of behavioral experiments aimed at exploring the directional sensitivity of the OR in two crab species belonging to different families: the varunid mud crab Neohelice granulata and the ocypode fiddler crab Uca uruguayensis. By using different conditions of visual perception (binocular, left or right monocular) and direction of flow field motion (clockwise, anticlockwise), we found in both species that in monocular conditions, OR is effectively displayed only with progressive (front-to-back) motion stimulation. Binocularly elicited responses were directional insensitive and significantly weaker than monocular responses. These results are coincident with those described in flies and suggest a commonality in the circuit underlying this behavior among arthropods. Additionally, we found the existence of a remarkable eye dominance for the OR, which is associated to the size of the larger claw. This is more evident in the fiddler crab where the difference between the two claws is huge. Fil: Barnatan, Yair Benjamín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Tomsic, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentina Fil: Sztarker, Julieta. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina

We analyze the role of bilateral symmetry in enhancing binocular visual ability in human eyes, and further explore how efficiently bilateral symmetry is preserved in different ocular surgical procedures. The inclusion criterion for this review was strict relevance to the clinical questions under research. Enantiomorphism has been reported in lower order aberrations, higher order aberrations and cone directionality. When contrast differs in the two eyes, binocular acuity is better than monocular acuity of the eye that receives higher contrast. Anisometropia has an uncommon occurrence in large populations. Anisometropia seen in infancy and childhood is transitory and of little consequence for the visual acuity. Binocular summation of contrast signals declines with age, independent of inter-ocular differences. The symmetric associations between the right and left eye could be explained by the symmetry in pupil offset and visual axis which is always nasal in both eyes. Binocular summation mitigates poor visual performance under low luminance conditions and strong inter-ocular disparity detrimentally affects binocular summation. Considerable symmetry of response exists in fellow eyes of patients undergoing myopic PRK and LASIK, however the method to determine whether or not symmetry is maintained consist of comparing individual terms in a variety of ad hoc ways both before and after the refractive surgery, ignoring the fact that retinal image quality for any individual is based on the sum of all terms. The analysis of bilateral symmetry should be related to the patients’ binocular vision status. The role of aberrations in monocular and binocular vision needs further investigation.

International audience; Purpose. Neuroimaging studies have shown that the dominant eye is preferentially linked to the ipsilateral primary visual cortex. However, its role in perception is still misunderstood. Here we examine the influence of eye dominance and eye dominance strength on saccadic parameters, contrasting stimulations presented in the two hemifields.Methods. Participants with contrasted eye dominance (left or right) and eye dominance strength (strong or weak) were asked to make a saccade toward a target displayed at 5° or 7° left or right of a fixation cross. In some trials a distractor at 3° of eccentricity was also displayed either in the same hemifield as the target (to induce a global effect on saccade amplitude) or in the opposite hemifield (to induce a remote distractor effect on saccade latency).Results. Eye dominance did influence saccade amplitude as participants with strong eye dominance showed more accurate saccades toward the target (weaker global effect) in the hemifield contralateral to the dominant eye than in the ipsilateral one. Such asymmetry was not found in participants with weak eye dominance or when a remote distractor was used.Conclusions. Here we show that eye dominance strength influences saccade target selection. We discuss several arguments supporting the view that such advantage may be linked to the relationship between the dominant eye and the ipsilateral hemisphere.; Introduction : La neuroimagerie suggère qu’il existe une relation privilégiée entre l’œil dominant et le cortex visuel primaire ipsilatéral. Cependant, le rôle de la dominance oculaire dans notre perception et notre action reste mal connu. La présente étude vise ainsi à étudier l’influence de la dominance oculaire et de sa force sur les paramètres saccadiques en manipulant l’hémichamp visuel dans lequel apparaissent les stimuli.Méthode : 92 participants étaient répartis en quatre groupes selon leur dominance oculaire (gauche ou droite) et sa force (forte ou faible). Leur tâche consistait à effectuer une saccade vers une cible présentée à 5° ou 7° d’excentricité, à gauche ou à droite d’une croix de fixation. Dans certains essais, un distracteur présenté à 3° accompagnait la cible, dans le même hémichamp (afin d’induire un effet global) ou dans l’hémichamp opposé (afin d’induire un remote distractor effect).Résultats : Chez les participants ayant une forte dominance oculaire, les saccades étaient plus précises (moins d’effet global) lorsqu’elles étaient dirigées vers une cible présentée dans l’hémichamp controlatéral à l’œil dominant que dans l’hémichamp ipsilatéral. Cet effet n’était en revanche pas présent chez les participants ayant une faible dominance oculaire. Par ailleurs, aucune différence entre hémichamps n’a été trouvée sur la latence des saccades lors de la présentation d’un distracteur éloigné.Conclusion : Cette étude montre que la force de la dominance oculaire module la précision de la sélection saccadique. Nous suggérons que cette modulation soit due à la relation privilégiée entre œil dominant et hémisphère ipsilatéral.

Handedness is the most obvious expression of lateralized behaviour in humans. However, there is only limited knowledge about other forms of lateralized behaviour, e.g. preferential use of an eye and whether these may correlate with handedness. Thus to investigate this, 100 subjects (50 males and 50 females) between 11 and 80 years of age were assessed for their eye preference, eye dominance, visual acuity, and handedness. Eye preference was assessed by performing four different monocular tasks, eye dominance by performing the binocular Dolman test, visual acuity was assessed with a Snellen chart and handedness was surveyed using the Edinburgh Handedness Inventory. Regarding eye preference, the right eye was preferred by 69% of the subjects. 90 % of the subjects were consistent for their preferred eye across all four tasks. 66% of the subjects had a dominant right eye, 33% had left eye dominance and 1% could not be assessed using the Dolman test. 56% of the subjects differed in their visual acuity between both eyes, while 43% had the same visual acuity in both of their eyes. 86% of the subjects were right-handed while 4% were left handed and 10% were ambidextrous. Significant correlations were found between visual acuity and eye preference and between visual acuity and eye dominance. The study also found a positive correlation between handedness and eye preference. These results support the notion that there is a weak correlation between the different aspects of lateralized behaviour in humans.

We previously found a dominant eye perceptional advantage in feature search (Vision Research, 2006). We now ask if this advantage extends to difficult conjunction search, which requires focused attention and depends on different cortical hierarchy levels. We determined eye dominance by the Hole-in-the-Card test. Using red–green glasses, subjects viewed a briefly presented, backward-masked, array of red/green dotted squares and filled circles. On half of the trials a filled square target replaced one dotted square. There was significantly better performance when the target was seen by the dominant eye, suggesting its visual processing priority in slow, as in rapid search, perhaps including augmented attention to dominant eye representations. Binocular conjunction targets were found faster than monocular targets, though binocularity—as utrocular information—was insufficient to support reasonable detection levels.

PubMedID: 16923688 The long-term effects of acute submaximal exercise on intraocular pressures (IOPs) of right-and left-eyes and recovery times to basement levels of IOP in postexercise periods in sedentary and physically fit subjects were investigated. Twenty-five sedentary and 24 physically fit subjects, ranging in age 17 to 22 years, participated. Intraocular pressures were measured by a pneumotonometer. Measurements were taken in the morning at about nine (at rest) and immediately, 30 min and 2 h after acute submaximal exercise. In sedentary subjects, IOPs of both right- and left-eyes decreased immediate after exercise, but, these decreases in both eyes continued 30 min and 2 h after exercise. In physically fit subjects, IOPs of both right- and left-eyes increased immediate after exercise, but decreased after 30 min exercise compared to basement levels, and this decrease continued 2 h after exercise. Acute submaximal exercise decreased IOPs of right and left eyes over a period 2 h in sedentary and physically fit subjects. IOP reducing after exercise was different between right- and left-eyes in sedentary subjects. These results suggest that exercise can be used in ocular hypertension treatment. Copyright © 2006 Informa Healthcare.

To test whether there is a relationship between handedness and the intraocular pressure and there is a lateralization in the intraocular pressure, the intraocular pressures of the right- and left-eyes were compared in right- and left-handed students. The intraocular pressures were higher in the right-eye than in the left-eye in men, right-handers, and right-eyed subjects; there was no right–left difference in females, left-handers, left-eyed, and both-eyed subjects. The intraocular pressure of right- and left-eyes was higher in left-handers than right-handers. And there were significant negative correlations between hand preference and the intraocular pressure of both right- and left-eyes. We have concluded that the dominant eye has higher intraocular pressure compared to the nondominant one, and there is a relationship between hand preference and the intraocular pressure.

The video eye-tracker can measure the direction of the visual axis of the eye based on the calibration, which creates a relationship between the displacement of a feature on the eyeball and the direction of the visual axis. However, this calibration method takes no account of the distance from the subject to the target. Version displacement of the pupil center was measured when the subject is fixating on stationary targets on the planes stood at different distances from the subject. As a result, the small transverse movement of the pupil center was observed when the subject had a version movement of the eyes for the targets on the near plane. The relationship between the distance and the amount of transverse movement was conspicuous in the dominant eye.

Sighting ocular dominance is the preference of one eye over the other in terms of sighting. In this study, our aim was to examine differences in interocular and intraocular macular thickness, interocular fovea-optic disc angle, and foveal blood vessel asymmetries associated with sighting ocular dominance. Ninety eyes of 45 healthy young adults were included in this prospective, cross-sectional, and comparative study. Sighting ocular dominance was determined by a hole-in-the-card test. Macular thickness measurements were taken and posterior pole asymmetry analysis conducted with spectral domain optical coherence tomography. The optic disc-fovea angle and visible foveal blood vessel counts were calculated by using the posterior pole retinal images of optical coherence tomography. The mean age of the participants was 27.3 (standard deviation [SD] 6.6) years. There were 20 males and 25 females. The mean total macular area thickness, and mean macular thickness of the superior and inferior hemispheres of the dominant and nondominant eyes were similar (p > 0.05). Macular asymmetry analysis revealed no statistically significant interocular difference (p > 0.05). In the dominant eyes, the mean optic discefovea angle was 5.24 degrees (SD 1.77), whereas it was 5.49 degrees (SD 2.58) in the nondominant eyes (p = 0.51). The number of visible blood vessels passing through the fovea was similar in the dominant and nondominant eyes (p > 0.05). These results suggested that interocular and intraocular macular thickness differences, interocular fovea-optic disc angle differences, and number of visible foveal blood vessels are not associated with sighting ocular dominance. Copyright (C) 2014, Kaohsiung Medical University. Published by Elsevier Taiwan LLC. All rights reserved.

We studied the role of eye dominance in non-rivalry conditions, testing dichoptic visual search and comparing performance with target presented to the dominant or non-dominant eye. Using red–green glasses, subjects viewed an array of green and red lines of uniform orientation, with a differently oriented target line present on half the trials. Performance was significantly better when the dominant eye saw the target, especially when the opposite eye saw the distractors. This effect was reduced when only nearest-neighbor surrounding distractors were homogeneous. We conclude that the dominant eye has priority in visual processing, perhaps including inhibition of non-dominant eye representations.