The magnitude of stereopsis in peripheral visual fields

Abstract

Methods: Sixteen volunteers (mean age, 21.1 ± 1.5 years old), with normal visual fields and stereopsis, were enrolled in this study. The subjects were asked to fix their attention on a central fixation target on the screen, and the stereopsis target was shown with a binocular disparity so that it stood out from the surrounding images. In this system, stereopsis targets were indicated randomly at 10° , 20° , and 30° on 8 meridians radiating from the central target. Results: The perception of stereopsis declined significantly the further away a target was from the central target (mean stereoacuity of 8 meridians radiating on 10° , 474 ± 202 arcsecs; 20° , 725 ± 704 arcsecs; and 30° , 1,223 ± 1,101 arcsecs). Moreover, stereoacuity from the central target to 30° directly below it tended to be better than that in other directions. Conclusions: When the stereo images appeared in the peripheral visual fields, normal subjects, between the ages of 20 to 22 years old, recognized stereo images of 3,600 arcsecs and over within the central 30° of the visual field. Furthermore, the stereopsis in the lower visual field was clearer than in the other visual fields.