Light absorption and scatter in the human lens.

The light transmission of freshly excised normal human lenses has been measured atfive visible wavelengths. The lens profile has also been recorded and used to calculate light lossper unit pathlength of lens. This loss, although made up of absorption and scatter thecontributions of which cannot be quantified, may be regarded as due to a hypothetical absorbingpigment. The loss is directly proportional to pigment concentration and remains constantthroughout the central 7-8 mm of the lens and between the ages of 20 and 60. Because of thisconstancy, senile lenticular yellowing is attributed to increasing lens thickness. The visualimportance of this light loss in the lens is briefly considered.