| Full text | |
| Author(s): |
Masili, Mauro
[1]
;
Duarte, Fernanda Oliveira
[1]
;
White, Christopher C.
[2]
;
Ventura, Liliane
[1]
Total Authors: 4
|
| Affiliation: | [1] Univ Sao Paulo, Dept Elect Engn, EESC, Av Trabalhador Saocarlense 400, BR-13566590 Sao Carlos, SP - Brazil
[2] NIST, Bldg & Fire Res Div, Gaithersburg, MD 20899 - USA
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | ENGINEERING FAILURE ANALYSIS; v. 103, p. 505-516, SEP 2019. |
| Web of Science Citations: | 0 |
| Abstract | |
In our previous investigations on sunglasses standards, limits and insertion of missing 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 44 unbranded sunglasses: 12 were submitted to a solar simulator (0.46 suns) for 2500 h and spectroscopy was performed every 25 h. The remaining 32 were submitted to a 10-sun solar simulator for 962 h of exposure, and transmittance spectroscopy and UV protection evaluation have been done. These exposure conditions are equivalent to wearing sunglasses for a period over 2 years, for 2 h 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 the majority of lenses will eventually fail the standard requirement, suggesting the revision of such aging test. Additionally, there has not been any significant alteration on UV protection. Summarizing, current parameters, for the resistance to radiation test for sunglasses on standards, is ineffective for ocular safety within its lifetime. In summary, current parameters for the resistance to radiation test for sunglasses, required by ISO 12312-1 standard, are ineffective for sunglasses average lifetime required by population. (AU) | |
| FAPESP's process: | 14/16938-0 - System to study the effect of natural sunlight and solar simulator on sunglasses: a contribution to the Brazilian Standard NBR15111 |
| Grantee: | Liliane Ventura Schiabel |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 13/08038-7 - Irradiance, radiant exposure, and ultraviolet index calculation for ocular protection |
| Grantee: | Mauro Masili |
| Support Opportunities: | Regular Research Grants |