Sunlight as an ultraviolet source.

An understanding of the spectral composition of sunlight is necessary if the effects of human exposure and protection criteria are to be meaningful. Also provided is a brief review of data for the ultraviolet UV solar spectrum in space and on earth that have been related to ocular damage. In addition, the effects of increases and decreases in the levels of ozone on the amount of ultraviolet radiation (UVR) reaching earth are presented. It is shown that enough UVR is encountered on earth to cause ocular damage and the damage will increase significantly as the levels of ozone decrease.