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Arquivos Brasileiros de Oftalmologia
Vol 67 - N 4 - 2004

Spectrophotometry of organic ophthalmic lenses of simple vision submitted to ultraviolet A and B radiation and visible light
Matsuhara, Mylene Leal; Machado, Liliana Rocha Galvão; Fernandes, Luciene Chaves

PURPOSE: To verify, by spectrophotometric study, the filtration power of A and B ultraviolet radiation and transmittance of visible light in colorless lenses of simple vision. METHODS: Spectrophotometric analysis (Model Humphrey Lens Analyzer LA 360 spectrophotometer) of 14 types of colorless ophthalmic lenses, made of organic material of different characteristics. Each lens type was represented by 20 copies, totaling a sample of 280 studied lenses. Later, the analysis of the transmittance curve in the spectrum range of 290 to 700 nm was performed. RESULTS: In relation to UVB radiation, all of the studied lenses presented transmittance from 0 to 1%. The ones that had a better performance (0% transmittance) were: Trivex, Rugged Fashion Wear, AO Lite, Hard Resin, Sola Light 1.56, MAR 1.56, MAR CR39, Stylis Crizal, Crizal, Air Wear, Orma 15. As for UVA rays, the transmittance oscillated from 1 to 18%. The ones that had a better performance (1% transmittance) were: Miolight Anti Reflex 1.56, Trivex, Miolight Excellence, Rugged Fashion Wear, Sola Light, MAR 1.56, Stylis Crizal e Air Wear. None of studied lenses completely filtered UVA radiation. All of the studied lenses presented transmittance over 95% in relation to the visible spectrum, with a variation from 95 to 100%. CONCLUSIONS: The studied colorless lenses present a real capacity of filtration of UV radiation, especially regarding the UVB spectrum, which is favorable since this is the main portion of the spectrum related to ocular damages. All of the studied lenses presented UVB filtration power from 99 to 100%, UVA from 82 to 99% and 95 to 100% of transmittance of visible light. The presence of such filters in colorless lenses increases the possibilities of prescription of this resource of ocular protection.