UV-A absorbing characteristics of commercial sunglasses intended for recreational and general use.

Ultraviolet radiation (UVR) is known to cause photokeratitis with acute symptoms. It also has been demonstrated that UVR has the potential to accelerate human cataractogenesis. For certain recreational pursuits, protection from specific UVR wavebands is important to the prescriber, the dispenser, and the patient or consumer of sunglasses. By knowing the ultraviolet absorbance characteristics of lens materials, practitioners would be able to advise their patients. In this study, the UV-A spectra of pairs of sunglasses purchased anonymously were measured. The results indicate that manufacturers' claims of UVR protection, or absorbance, are valid with respect to the UV-A waveband. No association between UV-A absorbance and lens material or cost was established.