Monocular occlusion impairs stereoscopic acuity, but total visual deprivation does not

Abstract

Wallach and Karsh (1963) reported that 24 h of monocular occlusion leads to a significant deterioration of stereoscopic depth estimates and attributed this phenomenon to "disuse." We designed an apparatus for testing stereoscopic accuracy which eliminated all cues to depth save binocular disparity. With it, we tested the relative effect of 8 h of monocular-;as opposed to binocular-;occlusion on subsequent stereoscopic performance. Monocular patching led to significant increases in mean standard deviation and in mean absolute error as compared to baseline testing. Binocular patching led to no such impairment. Thus, true disuse (such as occurs during binocular deprivation) did not impair stereopsis, whereas monocular occlusion, which may involve temporary misuse of the stereoscopic system, did. © 1974 Psychonomic Society, Inc.