A Study on the Spectral Transmittance of UV-Blocking Contact Lenses

Abstract

Purpose : The purpose of this study was to measure the spectral transmittance of domestic hydrogel contact lenses, and to find out if they meet the standards of visible light and UV-blocking spectral transmittance. Methods : Hydrogel contact lenses including UV-blocking contact lenses were randomly selected in this study. The range of spectral transmittance measurement in the experimental lenses was set to visible light, UV-A and UV-B. Visible light transmittance was based on ANSI Z80.20:2004. And the UV spectral transmittance was compared to the UV-blocking contact lenses standards applied by the International Organization for Standardization (ISO) and the Food and Drug Administration (FDA). UV-blocking contact lenses were classified as Class 1 and Class 2 according to the standards. Results : As a result of measuring visible light transmittance of 14 types of experimental lenses, 4 transparent contact lenses showed 88% or less, but did not deviate significantly from the range. And all 7 types of color contact lenses were measured to be over 70% and met the standards. In the spectral transmittance of UV, the UD-4, 5, 6 lenses among the 10 types of UV-blocking contact lenses showed the range of a spectral transmittance of 86.67~88.59% and 82.41~83.47% for UV-A and UV-B, respectively. These UV wavelength values were found to be non-compliant with ISO and FDA UV-blocking standards. Conclusion : It shows that some UV-blocking contact lenses do not meet ISO and FDA UVblocking standards, and they were all domestic products.