Experimental study of filtered light effect in the retina. Its aplication for car windows.

Abstract

Purpose: exposure ot light seems to be the triggering factor for some age-related retinal diseases, although the portion of the visual spectrum responsible for damage to the retina is as yet unknown. The present study was designed to investigate the role of circadian exposure to white, blue and yellow light on the retina Materials and methods: Adult albino rats were exposed to white, yellos or blue light for 15 days. The animals were sacrificed and the eyes removed and processed for light microscopy. Results: Exposure to white light does not modify the structure of the retina. The retinas of the rats exposed to yellow liht showe a thinner outer plexiform layer, reduced cell numbers in the inner and outer granular layers, and occasionally a lack of photoreceptor external segment of the photoreceptors was absent, and the density of cells severely reduced. Further, most of the animals showed enlarged and dilated choroidal blood vessels. Results were confirmed by quantitative histological techniques. Conclusions: Light exposure induces several retinal changes, with blue light inducing the most remarkable changes. Car windscreens could be a goo support system for the use of filters to block blue light.