An Objective Study of Binocular Vision

Abstract

The traditional explanation of binocular fusion rests on the assumption of corresponding retinal points. The mathematical definition of these points has been given by Helmholtz, who wrote, Identisch sind solche Punkte beider Gesichtsfelder, welche gleiche H6henwinkel und gleiche Breitenwinkel haben.' Hering utilized the principle of corresponding points in his theory of space-feeling.2 His theory of stereopsis, however, had its origin in the view advanced by Panum that binocular fusion did not result from point-to-point correspondence, but rather from point-to-area correspondence. Panum wrote, ein jeder empfindende Netzhautpunkte des einem Auges einen correspondirenden Empfindungskreis ... in anderen Auge hat.3 Since Hering most of the investigators of binocular vision have accepted the nativistic hypothesis, and have relied upon the assumed identity of the retinal structure for the explanation of binocular fusion. In addition to this a relationship between accommodation and convergence has been assumed. The methods employed to test this relationship have proceeded on the assumption that binocular fusion involves the stimulation of corresponding points. The present study is concerned with this latter assumption.