A Fluorescent Substance of Low Molecular Weight in the Lens of Primates

Abstract

It has long been known that the lens shows a marked fluorescence in ultraviolet light (Regnauld, 1858). This fluorescence is most intense at wavelengths of 360-370 mμ. In man, Hosoya (1929) found the region of lenticular fluorescence to be between 410 and 310 mμ for subjects aged 10-45 and between 425 and 310 mμ for subjects aged 75. Lenticular fluorescence is not a specific characteristic of man. Brolin and Cederlund (1958) observed it in fishes, amphibians, birds, and mammals. These authors observed that its intensity is constant in the same species but markedly differs from one species to another. The fluorescent spectrum—continuous and similar in all cases—extends from 410 to 700 mμ. Maximal energy emission is between 500 and 520 mμ. The cause of lenticular fluorescence is still largely unknown, and this explains the divergence of opinions; it was not until 1948, moreover, that this fluorescence could be more