INDUCED SIZE EFFECT

Abstract

In the first paper of this series¹ the general aspects of a new phenomenon in binocular vision, designated as the induced size effect, was discussed. The nature of this phenomenon will be clear from the following explanation : When a change in the relative sizes of the images of the two eyes is introduced in the horizontal meridian by placing a meridional size lens before one eye, all objects in a binocular visual field relatively free from strong perspective clues appear as though rotated a certain amount from their original positions about a vertical axis through the fixation point. This apparent rotation of the binocular visual field is to be expected, for obviously it depends on the binocular depth perception that arises from horizontally disparate retinal images. Any change in the relative size in the horizontal meridian will necessarily change the disparities of the retinal images, and, accordingly, new stereoscopic