The effect of photopigment optical density on the color vision of the anomalous trichromat

We present a theoretical model to estimate the influence of photopigment optical density (OD) on the color vision of anomalous trichromats. Photopigment spectral sensitivities are generated using the Lamb (1995) template, which we correct for OD and pre-receptoral filters. Sixteen hyperspectral images (Foster et al., 2004 and Nascimento et al., 2002) are analyzed, and the signals produced in the post-receptoral channels calculated. In the case of anomalous trichromats whose two longer-wavelength cones have peak sensitivities that lie close together in the spectrum, color vision can be substantially enhanced if the cones differ in optical density by a realistic amount.

► Photopigment optical density (OD) varies between observers.
► We model the effect of OD variation on anomalous trichromatic color vision.
► OD variation affects the predicted quality of color vision of anomalous trichromats.
► A difference in OD of 0.1 might be as valuable as an extra 1 nm peak separation of photopigments.