ULTRAVIOLET TRANSMITTANCE OF CONTACT-LENSES

Chronic and acute exposure to ultraviolet (UV) radiation has been shown to have deleterious effects on all layers of the human eye. As a consequence, appropriate protective measures have been advocated with respect to exposure to this form of radiation. Among suggested actions are spending less time in the sun and wearing protective visual aids such as those containing UV-absorbing materials when exposed to sunlight. To investigate the protective ability of currently available contact lens materials we measured the transmittance characteristics of 11 different types of soft and rigid contact lenses in the UV and visible range from 280 to 500 nm with a Zeiss model DM4 Dual Beam Spectrophotometer. Our findings indicate that lenses not treated with UV absorbers transmitted most of the UV radiation. Lenses containing UV absorbers provided excellent UV protection and transmitted significantly less UV radiation than the untreated lenses (Student's t-test with Bonferoni's correction, N = 10, p < 0.001). Based on our findings, we recommend that contact lenses with UV absorbers be considered as a viable option for providing UV protection, especially for aphakic patients, patients taking photosensitizing pharmaceutical agents, and those patients who spend a great deal of time outdoors.