Environmental near-UV radiation and cataracts.
This report compares sunlight UV-A and UV-B fluxes in the Northeastern United States that reach the crystalline lens with thresholds that cause lens damage. The fluxes of UV-A and UV-B radiation that reach earth to penetrate the cornea and to reach the lens were calculated. Ten hours of continuous UV-A exposure or 23 min of UV-B would exceed the rabbit cornea threshold for photokeratitis. The lens threshold would be reached by 26 h of UV-A or 245 h of UV-B continuous exposure. The sequence of UV-induced damage follows: (1) UV-B photokeratitis; (2) UV-A photokeratitis; (3) UV-A lens damage; and (4) UV-B lens damage.
Zigman
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Department of Ophthalmology, University of Rochester School of Medicine and Dentisty, New York, USA.
D000818:Animals; D002386:Cataract / Q000209:etiology*; D003315:Cornea / Q000528:radiation effects; D004781:Environmental Exposure; D006801:Humans; D007908:Lens, Crystalline / Q000528:radiation effects*; D011817:Rabbits; D011832:Radiation Injuries / Q000209:etiology*; D011833:Radiation Injuries, Experimental / Q000209:etiology; D012589:Sciuridae; D012684:Sensory Thresholds; D013472:Sunlight / Q000009:adverse effects; D014466:Ultraviolet Rays / Q000009:adverse effects*