The effect of perceived distance on accommodation under binocular steady-state conditions.

Spatiotopic cues, such as perceived distance, have little effect on accommodation unless blur has been reduced or eliminated. We investigated the effect of perceived distance on accommodation under binocular steady-state conditions, about which little is known. Blur was reduced but not eliminated by using a stimulus with a moderately low luminance. Accommodation was measured under two conditions: (1) when cues from perceived distance, blur, and convergence were aligned; and (2) when perceived distance was opposed by both blur and convergence. We found a significant difference in accommodation between the two conditions, which we attribute to perceived distance.