Ocular effects of ultraviolet radiation, 200-400 nm, are reviewed. Depending upon the exposure parameter involved, UV radiation may be harmful to the cornea, lens and/or retina. Ranges of exposure parameters (wavelength, exposure duration, etc.) for which each of the tissues is susceptible are specified and the nature of the tissue is described. Present understanding of the thermal and photochemical damage mechanism operative for various conditions of exposure are discussed Ocular damage thresholds for wide ranges of exposure parameters are summarized and compared to existing safety standards.