Abstract
Abstract: :
Purpose: One-eyed subjects have better visual acuity for contrast-defined stimuli than two-eyed subjects viewing monocularly. In addition to the recruitment of the missing eye’s resources by the remaining eye, the lack of inhibitory binocular interactions may account for some of that superiority. As a consequence of the absence and presence of binocular rivalry, Troxler fading should be reduced in one-eyed observers and increased in monocularly-viewing controls, respectively. Methods: We analyzed the time to fading of peripheral targets as a function of brightness contrast in two groups of observers. Those in the control group (n=30) had normal binocular vision and were tested monocularly (with an eye patch) and also binocularly. The observers in the second group (n=11) had all been eye-enucleated at an early age due to reinoblastoma. Results: Time to fading was a function of contrast for both groups. Data from the control group showed Troxler fading to be significantly faster with patched than binocular viewing at high and medium contrast levels. One-eyed observers showed significantly higher times to fading than two-eyed subjects viewing monocularly and equivalent times to binocular viewing. Conclusions: The absence of binocular rivalry may explain in part the monocular observers’ better performance in contrast-defined acuity tasks.
Keywords: binocular vision/stereopsis • plasticity • retinoblastoma