Spectral sensitivity of single visual cells

Abstract

SINCE the work of Young and Helmholtz, the highly developed colour vision in man and many animals has been thought to depend on several, usually three, retinal receptors with different spectral sensitivity1,2. Such a theory is best suited for the explanation of human sensations, of animal reactions, and of electrical responses of the whole eye. It is, however, very difficult to determine the spectral sensitivity of the postulated single receptors using these methods. The existence of different photosensitive pigments has been demonstrated by chemical methods in vertebrates3, and in vivo photometric measurements have shown them for the mammalian retina4. But this again does not give us an entirely satisfactory explanation of the principal unit-level functions, and the very successful chemical analyses of the visual pigments do not help us understand colour vision5. © 1961 Nature Publishing Group.