Ocular hazards arising from depletion of the natural atmospheric ozone layer: a review

The processes contributing to the maintenance of the natural, atmospheric, ozone layer, which screens the earth's surface from solar ultraviolet radiation at wavelengths below 300 nm, are described. The possible adverse effects of man-made chemicals such as chlorofluorocarbons (CFCs) on this layer are outlined. Consideration of the flux of ultraviolet light reaching the earth's surface as a function of the ozone concentration and other factors allows the effect of ozone changes on ocular health to be evaluated. It is concluded that the changes of the order of a few per cent that are predicted by current models of the atmosphere, and which are comparable with natural fluctuations in ozone, would have relatively little effect on the incidence of solar keratitis at the cornea. Larger changes, in the order of 50%, would be expected to have a significant effect. There might also be an increase in the incidence of brunescent cataract. Ozone changes would have a negligible effect on the amounts of solar radiation reaching the retina.