AbstractThe optical density for the noncataractous crystalline lens is written as a sum of two terms, each with a specific dependence on wavelength. The first term, proportional to 1/2, represents all light-scattering processes in the lens. The second term, assumed significant only for A ≤ 500 nm, accounts for absorption by lens pigments. By analyzing transmittance data on lenses of subjects aged 21 to 63 years, a spectrum for light absorption by lens pigment is derived and it is shown to be essentially the same for all of the lenses.