Some biochemical aspects of light effects on transparent eye tissues

The usefulness of biochemical studies on effects of light on transparent tissues of the mammalian eye is discussed in relation to the possible role of photobiological phenomena in aging and pathology of the eye. Particular emphasis is on effects of light on interaction between different cellular constituents of the corneal stroma which appear as a factor in regulation of the corneal metabolism. Daylight filtered through the walls of glass vessels was found to depress the incorporation of 14-C glucosamine into keratansulfate fraction of the bovine corneal stroma which appears not to be bound to collagen fibrils as it is extracted by 0.15M NaC1 at 4 degrees C without any morphological change in these fibrils. Since this depression was not found in the absence of the epithelium, secretions by the epithelium of specific substances affecting the keratoyctes are suggested. The possible relation of light effects on the hydration of the cornea is discussed.