The use of size matching to demonstrate the effectiveness of accommodation and convergence as cues for distance

Abstract

The capacity of accommodation and convergence to serve as cues to distance was assessed. As is usual, size perception was employed as an indicator. The standard technique of obtaining size matches between figures of identical shape yielded poor results. The inadequacy of this technique was revealed when matching the length of two edges that were parts of different figures produced nearly veridical results. A tendency to match image sizes was held responsible for the failure of the standard technique. The absence of extraneous distance cues from our experimental conditions was demonstrated with the help of spectacles that altered the accommodation and convergence with which objects were viewed. © 1971 Psychonomic Society, Inc.