Ocular dominance

Ocular dominance ( technical term ocular dominance of Latin oculus "eye" and dominus "lord" ) refers to the fact that the retinal image of one eye of a living being, opposite the retinal image of the other eye is preferred.

In binocular vision the eyes are spatially positioned differently, thereby vary their retinal images, the retinas are so taken by different light beams. When the two retinal images are sufficiently similar (otherwise there is the binocular rivalry ), the brain will combine them together to form a single image by the visual information of the non-dominant eye is "shifted" to the dominant eye. This process is called fusion.

Which eye dominant?

To determine the ocular dominance there are various methods. For many, the subject is asked a closer ( for example, the own thumb with outstretched arm ) and a Ferrieres object (such as a vertical line on a wall ) coordinate ( position, for example, the thumb so that it lies on the line ) and the to fix more object. Now, the subject is asked to close his eyes alternately. Does it include the non-dominant eye, the perceived position of the objects does not change each other, since the binocular perception is already tuned to the dominant eye. However, where the subject's dominant eye, the position of objects change each other, since the visual information of the non-dominant eye can not be adapted to the dominant eye.

Eye dominance can vary in strength and is not directed forcibly afterwards, with which eye you can see better. At approximately two-thirds of people dominates the right eye; this is consistent with the observation that there are more right-handed than left-handed. Which eye dominates, but seems to vary with the viewing direction during the test; the decisive criterion is seemingly on which of the two retinas the image of the observed object is larger. In individuals with the Williams -Beuren syndrome, which is caused by a genetic defect and can, among other things lead to defective vision, the left eye seems to be more common dominant than the right. Possibly also in migraine patients, the left eye is often dominant, the experimental findings are not yet conclusive here. In amblyopia, a developmental disorder caused by childhood permanent visual impairment in one eye dominates the more functional eye. In anisometropher myopia, ie, when the visual acuity of the eyes (significantly) differs, however, dominates the kurzsichtigere eye.

Effects

The dominant eye seems to be taking a predominant role in the visual perception; so for example it is not only faster for search tasks, but seems to suppress even delivered by the subordinate eye impressions.

Impaired vision of the dominant eye are much more clearly perceived as impairment of the child 's eye. This affects the treatment methods of cataract surgery and refractive surgery as well as the fitting of contact lenses: In order to achieve satisfactory results, has the vision of the dominant eye are as comprehensively restored; Restrictions on child eye, however, are more bearable.

Lying dominant eye and dominant hand on different sides of the body, it is called cross dominance. Studies suggest that cross- dominance has a positive impact on the objectives, such as when trap shooting and golf.

Left-sided and reciprocal ocular dominance are common with left-sidedness generally suspected to cause learning difficulties or favor.

Measurements of eye movements with eye tracking, the system must be especially calibrated to the dominant eye in order to provide reliable results.

Causes

The cause of ocular dominance, as well as on the right - or left-handedness, the dominance of one cerebral hemisphere accepted. In the development phase of the vision created in the visual cortex, the area of ​​the brain, are processed in the visual impressions, known as ocular dominance columns ( english ocular dominance columns, ODC). These columnar networks of neurons that can be identified as a striped pattern on the exposed brain, align themselves with either an axon of the right or left eye, extending over several layers of neurons. Normally, the ocular dominance columns are distributed approximately evenly on both eyes, but during the development phase of an eye inoperative so grow only the columns of the other eye and take the visual cortex for a. Presumably, the formation of ocular dominance columns for ocular dominance is responsible for binocular vision and depth perception.

Swell

• Physiology of the eye