Ultraviolet transmittance of the Vistakon disposable contact lenses.
With increasing scientific evidence demonstrating the harmful effects of ultraviolet (UV) radiation on different ocular tissues, contact lens manufacturers are incorporating UV blocking monomers into their contact lenses. This study evaluated the transmittance spectra of Vistakon's disposable soft contact lenses (1 Day Acuvue, Acuvue, Surevue, and Vistavue). All except Vistavue contain a UV blocking agent. Transmittance for each lens was recorded from 200 to 400 nm on a Shimadzu UV 160U Dual Beam Recording Spectrophotometer. The results indicate that lenses which incorporate the UV blocking monomer significantly reduced the transmission of W radiation while untreated lenses did not. Our findings indicate that 1 Day Acuvue, Surevue, and Acuvue meet the American National Standards Institution (ANSI) Standard Z80.20 for Class 2 UV blockers: a maximum of 30% transmittance of UVA wavelengths and 5% transmittance of UVB wavelengths. In contrast, the Vistavue lens demonstrated negligible UV blockage. Our technique, in which contact lenses were placed directly in front of a measuring beam, was accurate and simpler than previously reported methods and may be useful in future studies. We found that UV blocking soft contact lenses can be a viable alternative for spectacles in protecting internal ocular structures from UV radiation. However, the external structures of the eye remain at risk and would continue to benefit from the use of UV blocking sunglasses or spectacle lenses.
Harris
M G
MG
Department of Economics, University of California, Berkeley, CA 94720-2020, USA.
Chin
R S
RS
Lee
D S
DS
Tam
M H
MH
Dobkin
C E
CE
Dobkins
C E
CE