Color: Genetics of

Normal trichromatic color vision in humans is afforded by the presence of three types of light sensitive cone photopigments in the retina. The underlying genetics of the short-, middle-, and long-wavelength sensitive (abbreviated S, M, and L) cone photopigments has been the topic of research for nearly 300 years. However, only during the past 20 years, through the use of modern molecular genetic techniques, has precise information about the genes underlying normal and defective color vision become available. This entry examines the current understanding of the genetic basis for human color vision, genetic variability in the system, and its behavioral consequences.