Re: What is 'eye dominance'?

Paul Armstrong:

     "Eye Dominance" refers to the eye that the brain "prefers" or one that 
has stronger "processing" in the brain than the other.  People usually have 
one eye that likes to "take over" when binocular vision is impaired, or one 
eye that is more sensitive to visual descrimination.  

     One advantage for having eye dominance would be for hunters or 
sharpshooters.  Usually it is recommended that one use the dominant eye to 
line up the sights for the reason mentioned above, because visual acuity, 
or discrimination is better, thus resulting in better accuracy.  In any 
activity, in which fine monocular coordination and vision is required, the 
dominant eye certainly has an advantage.

     During suppression, when the brain "chooses" to process only one eye, 
the other eye is in essence "shut down".  The brain is a very complex yet 
simple organ in which a vast amount of visual information can be processed 
simultaneously or can  completely disregard information from the one eye. 
Usually suppression occurs only in those who have no binocularity, usually 
congenital, and it is their only adaptive mechanism to avoid double vision. 
 People with dominant eye can have very normal vision and binocularity.

     Usually it makes no difference in correcting for visual defects with 
eyeglasses or contacts.  Maximum correction in both eyes is achieved.
For monvision patients, the dominant eye is usually set for distance.

     There is a simple in-office test to determine eye dominance.  It is a 
simple procedure.  First, the individual engages a small target with both eyes 
open through a small opening made by clasping your hands together.  When the 
opening is 
small enough to barely see your target, close one eye, then the other.  The 
non-dominant eye will not see the target with the other eye closed.  However, 
some people have no dominant eye or an alternating dominance and no difference 
is observed.

     Unless you want technicality or a research paper level of information, I 
would reccommend www.aoanet.org.  Otherwise, a health sciences library should 
have sample texts and periodicals which can guide you in your search.

I hope this helps and good luck to you.

K. McWilliams