Degradation of sunglasses filters after long-term irradiation within solar simulator

Published

September 18, 2019

Author(s)

Deborah Jacobs, Mauro Masili, Fernanda O. Duarte, Liliane Ventura, Christopher C. White

Abstract

In our previous investigations on sunglasses standards, limits and requirements have been suggested for ocular safety. In this paper we evaluate the degradation of the lenses (category and ultraviolet protection) as sunglasses are exposed to solar radiation for periods considered still within its lifetime. Our study includes 47 unbranded sunglasses: 15 were submitted to solar simulator (0.46 suns) for 2500 h and visible and UV transmittance spectroscopy was performed every 25 h of exposure. The remaining 32 samples were submitted to for 962 h of NIST SPHERE exposure, and visible and UV spectroscopy was acquired. These exposure conditions are equivalent to wearing sunglasses for a period over 2 years, for 2 hours daily. Standards require 50 h exposure as the aging test. Under this condition, only one lens failed the requirement. However, our longer-term irradiation (sunglasses desired lifetime period exposure) experiment in solar simulator shows that most lenses will eventually fail the standard requirement, suggesting the revision of the aging test. Additionally, there has not been any significant alteration of UV protection. In summary, this research shows that while the sunglasses pass current standards (ISO 12312-1) for ocular safety, longer term exposures show significant degradation in protection within the design life of the lens.

Citation

Polymer Degradation and Stability

Volume

103

Pub Type

Journals

Keywords

ISO 12312-1, sunglasses, polymer degradation, UV spectroscopy, visible spectroscopy, solar radiation

Citation

Jacobs, D. , Masili, M. , Duarte, F. , Ventura, L. and White, C. (2019), Degradation of sunglasses filters after long-term irradiation within solar simulator, Polymer Degradation and Stability (Accessed November 21, 2024)