Although it is generally accepted that ultraviolet (UV) radiation has the potential to provoke the development of opacities within the crystalline lens, the exact role of sunlight as a factor in the reduction of the clarity of the crystalline lens appears controversial. Endorsement for a correlation between lens opacification and UVB (290-310nm) radiation has been provided by several geographic/epidemiological studies, which demonstrate a relationship between UVB radiation and the prevalence of lens opacification. In addition, experimental studies have shown that artificial sources of UVB radiation produce lens opacities in animals both in vivo and in vitro.