A theory of the induced size effect

A quantitative formulation of Ogle's induced size effect is carried out on the assumption that vertical equality of the retinal images acts as a cue for localing the subjective median plane as opposed to the horizontal retinal dispartities which serve for localizing the subjective frontal plane; that this cue operates, independently of such cues as are provided by ocular versions, and predominates when the versions are not great. The equation which embodies the theoretical predictions involves no parameters not directly measurable.