An action spectrum for the production of transient tritanopia.

The site of yellow/blue chromatic-opponency has been thought to include synergistic input from either or both of the longwave-sensitive cone types to the "yellow" side. It has remained controversial whether one of these cone types provides all the "yellow" input or if both contribute to some extent. By measuring the action spectrum of adapting fields that produce transient tritanopia at their offset it appears that both the red- and green-sensitive cone types contribute in approximately the same ratio that they contribute to luminance. There also appears to be a contribution from an antagonistic red/green mechanism in producing transient tritanopia. These seem consistent with current physiological and psychophysical evidence.