Contour interaction and temporal masking in strabismus and amblyopia

Visual acuity of amlyopic eyes, measured under binocular viewing conditions, was improved by reducing the contrast of targets presented to the normal eye. Improvement was also obtained by adjusting the temporal relationship between inputs to the normal and amblyopic eye. Optimal acuity was obtained by alternately presenting targets to the two eyes at rates centered about 2 and 7 Hz. These results are interpreted in terms of binocular contour interaction and metacontrast suppression. They suggest that a portion of the amblyope's acuity loss during binocular viewing conditions results from excessive masking by the dominant normal eye.