Rapid Chromatic Adaptation of Normal and Dichromatic Observers*

A large number of spectral sensitivity curves has been obtained for three observers: a normal, a deuteranope, and a protanope, by means of a rapid chromatic adaptation technique. Sensitivity curves for several adapting luminances and colors have been obtained. It has proved possible to fit these data by summing three hypothetical underlying sensitivity functions which are applicable to all three observers. The analysis of the theoretical fits appears to be in support of the concept of protanopia as a lack of “red cones” and of deuteranopia as a fusion of the inputs from “red” and “green cones.” There is evidence that chromatic adaptation is not, however, as selective as the hypothetical underlying sensitivity functions require.