Transmittance analysis in sunglasses lenses following sun exposure

Abstract

The hypothesis that sunglass ultraviolet (UV) protection can degrade with Sun exposure has never been proven experimentally. No sunglasses standards take into account UV transmittance changes after long Sun exposure. We selected 12 sunglass lenses and measured transmittance values from 280 nm to 780 nm. After 50 hours of exposure, new transmittance measurements were taken and transmittance variations inferior to 0.2% were observed. The exposition continues longer and more lenses will be tested to obtain conclusive results. We hope to obtain experimental data to confirm UV protection loss hypothesis and obtain a relation between Sun and solar simulator exposition.