Abstract
Purpose :
We previously reported that the sensory dominant eyes tend to be more myopic in myopic anisometropes and less hyperopic in hyperopic anisometropes. This may suggest some fundamental difference between the dominant and non-dominant eye in the process of emmetropization. However, the previous study was done at one near distance, 60cm away from the target. It is not clear if the sensory dominant eye changes at different viewing distances. In this study, we investigated whether the sensory dominant eye remains the same or switches at near and far viewing distances.
Methods :
The ocular sensory dominance was quantified in 70 subjects with a technique that involves the dichoptic presentation of a Mondrian noise and a Gabor patch. The threshold to detect the Gabor patch was measured in the presence of decreasing contrast in the Mondrian stimulus. Each eye was tested 50 times and thresholds from two eyes were compared with t-test. If the difference between the two eyes was significant, a subject was classified as having clear ocular sensory dominance and the eye that had lower threshold was defined as the dominant one. If difference between the two eyes was not significant, a subject was classified as having unclear ocular sensory dominance. Ocular sensory dominance was measured at two different viewing distances, one for near at 60cm away and the other one for far at 6m away.
Results :
In 41 subjects (58.6%), dominant eyes remained the same for both far and near condition. In 11 (15.7%) subjects, who showed clear ocular sensory dominance at far, ocular sensory dominance became unclear at near. 13 (18.6%) subjects that had unclear ocular sensory dominance at far showed clear ocular sensory dominance at near. In 5 (7.14%) subjects, the dominant eyes switched between far and near distances.
Conclusions :
The effect of viewing distance on ocular sensory dominance is a continuous spectrum. In majority of the population, ocular sensory dominance is not affected. In 1/3 of the population, ocular sensory dominance varies between unclear and clear status. Only in very rare cases, dominant eyes switch between near and far.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.