Convergence and stereoscopic vision.

Abstract

Stereoscopic acuity measurements for eleven observers, under three different conditions of observation, were taken using a semi-automatic instrument, which is a modification of Wright's instrument. The apparatus provides two circular targets seen against a black background. The results of the eleven observers, together with those of three observers for whom similar measurements were taken in a previous investigation, are statistically studied. The analysis of the results supports the view that convergence is a factor contributing to stereoscopic vision.