Abstract

Color matching data provides the basic data set for derivations of the cone photopigment fundamentals. Central to the power of the color matching technique is its property of linearity, which presumably arises from the univariance of the photoreceptors. However, there are three well-known experimental conditions which cause failures of linearity. These conditions are changes in test field size (the color-match area-effect), increasing the retinal illuminance above about 5000 td (the color-match illuminance effect), and changing the point of pupil entry of the color matching field (the Stiles-Crawford II effect). Explanations for these effects include changes in the optical density of the photopigments⁹, and changes in the wavelength dependent waveguide properties of the cones. Previous studies^2,6,10, have argued that neither the illuminance effect nor the SC II effect can be explained by optical density, however these studies rely on computational models of the effect of pupil entry and bleaching. In this paper we directly manipulate the optical density of the cones by bleaching.

© 1992 Optical Society of America