Colour Perception in Parafoveal Vision

Abstract

Quantitative studies of extra-foveal colour vision are inherently difficult owing to the poor discrimination and rapid adaptation found in the parafoveal and peripheral areas of the retina Measurements of the luminosity, colour mixture and hue discrimination curves have been made by a single observer using a field subtending 1° 20' and located at 2° and 4° from the fovea. The results suggest that for high retinal illumination parafoveal colour vision does not differ in essential characteristics from foveal colour vision, but at low illuminations colour perception becomes reduced to a type of dichromatic vision similar to the tritanopic form of defective colour vision and to that reported for small-field foveal vision.