Optical density of the aging human ocular media in the visible and the UV.

We analyzed the literature on the absorption in the young and aging human eye media. Five templates were derived to provide an adequate description of the spectra from 300 to 700 nm for the lens, cornea, aqueous, and vitreous. Two templates were found in all media. They stand for Rayleigh scatter and the absorbance of tryptophan. Three additional templates for the lens represent absorbance in kynurenine derivatives, such as 3-hydroxykynurenine glucoside (3HKG), and absorbance in two substances found at older age. Except for Rayleigh scatter, all templates have a Gaussian shape. Aging-trend functions were derived that show a linear slope on an age-squared scale. The result can be used to correct for media losses in visual perception tasks, in fundus reflectometry, and in studies on light damage.