Spectral sensitivity of color-blind observers and the cone photopigments

Abstract

A comparison was made between Dartnall's standard shape for visual pigments and the spectral sensitivities of the short-, middle-, and long-wavelength sensitive cone receptor mechanisms of man Data from blue monocone monochromats, protanopes, and deuteranopes were chosen as reliable estimates of each of the three classes of cone sensitivities The shortwavelength sensitive mechanism fits the standard shape The middle- and long-wavelength sensitive mechanisms have the same shape on a wavenumber axis but do not fit Dartnall's standard shape for visual pigments The shape of the middle- and long-wavelength sensitive mechanisms also describes some other published absorption spectra of visual pigments with λ max > 520 nm , notably the lodopsins found in birds.