Revista Brasileira de Oftalmologia
Print version ISSN 0034-7280
PORTES, Arlindo José Freire et al. Ultraviolet filter effect on hydrophilic high hydrated contact lenses. Rev. bras.oftalmol. [online]. 2008, vol.67, n.3, pp. 114-118. ISSN 0034-7280. http://dx.doi.org/10.1590/S0034-72802008000300003.
The exposure to ultraviolet radiation is associated with the beginning of ocular pathologies like keratites, cataract, age-related macular degeneration and pterygium. This radiation is divided in 3 bands according to the wave length: Uv-A (320-400), Uv-B (290-320), Uv-C (100-290). The optic industry developed ultraviolet filters to intraocular lenses, contact lenses and spectacle lenses. PURPOSE: The issue of this work is to estimate the efficacy of ultraviolet contact lenses with high hydration. METHODS: Six types of high hydrated contact lenses from different brands with three new equal units were evaluated, observing the transmittance rates of light energy in the wave bands between 200 to 400 nm measured with spectrophotometer. RESULTS: Three groups that had ultraviolet filters blocked sharply the Uv transmittance from 400 nm to 340 nm. There was an increase in Uv transmittance between 240 nm to 300 nm up to 45%. Below 240 nm and between 300 nm and 320 nm there was a complete Uv block. The three contact lenses types that didn't have ultraviolet filters block sharply Uv radiation below 240 nm and below 220 nm there was a complete Uv block . CONCLUSION: Contact lenses that diddn't have UV filter didin't block efficaciously Uv-A, Uv-B or Uv-C. The ultraviolet filter have blocked the Uv-B radiation almost completely, and partially the Uv-A and Uv-c.
Keywords : Contact lenses; Ultraviolet rays [adverse effects]; Filters; Radiation ; Eye diseases [etiology].