Metabolic production of a blue-green fluorophor in lenses of dark-adapted mice and its increase with age.

A blue-green fluorophor (496 nm emission/406.7 nm excitation) occurs in the mouse lens; its increase with age is more pronounced in the nucleus than in the cortex. The level of fluorophor and its rate of production are the same for animals reared in the dark as for animals reared in the light. Thus, the fluorophor is not generated by a photochemical reaction but is a purely metabolic product.