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Updated: May 31, 2026

Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition
Published on: July 21, 2020
Human stereopsis is not limited by the optics of the well-focused eye
Björn N S Vlaskamp1, Geunyoung Yoon, Martin S Banks
1Vision Science Program and School of Optometry, and Department of Psychology, University of California, Berkeley, Berkeley, California 94720, USA.
Abstract:
Human stereopsis, the perception of depth from differences in the two eyes' images, is very precise: image differences smaller than a single photoreceptor can be converted into a perceived difference in depth. To better understand what determines this precision, we examined how the eyes' optics affects stereo resolution. We did this by comparing performance with normal, well-focused optics and with optics improved by eliminating chromatic aberration and correcting higher-order aberrations. We first measured luminance contrast sensitivity in both eyes and showed that we had indeed improved optical quality significantly. We then measured stereo resolution in two ways: by finding the finest corrugation in depth that one can perceive, and by finding the smallest disparity one can perceive as different from zero. Our optical manipulation had no effect on stereo performance. We checked this by redoing the experiments at low contrast and again found no effect of improving optical quality. Thus, the resolution of human stereopsis is not limited by the optics of the well-focused eye. We discuss the implications of this remarkable finding.
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