Visual pigments in dichromats

Abstract

Cone pigments in protanopes and deuteranopes were measured by retinal densitometry, and the energy of various monchromatic lights found that bleached at a fixed rate of 25 per cent total pigment per minute. The same bleaching lights were matched with a fixed yellow in a bipartite field. Lights matched for bleaching were found to look equally bright to dichromats. It is concluded that the pigments measured by densitometry are visual pigments; their action spectrum coincides closely with the spectral sensitivity curves of Pitt for protanopes and deuteranopes.