ULTRAVIOLET RADIATION ABSORPTION BY SUNGLASSES AVAILABLE THROUGH IRANIAN OPTICIAN TRADE UNION AND MISCELLANEOUS VENDORS

Purpose: To compare the protection of eyes against visible light (VL) and ultraviolet radiation (UVR) by sunglasses available through the Iranian optician trade union (IOTU) shops and those provided by miscellaneous vendors. Methods: Totally, 353 pairs of sunglasses, including 188 pairs from IOTU shops and 165 pairs from miscellaneous vendors were selected based on systematic random sampling. The amount of UVA, UVB and VL transmission of the samples were examined by spectrophotometer. American national standard institute (ANSI) standards were the reference for measuring the UV transmission. Results: All of the sunglasses from IOTU shops met ANSI standards in transmission of UVA, UVB, while these percentages in miscellaneous vendors were 92.1% for UVB and 95.8% for UVA transmission (P<0.05). Mean of UVB transmission was 0.78% in IOTU shops and 1.8% in miscellaneous vendors. These percentages for UVA transmission was 0.92% and 7.1% respectively (P≤0.001). All of the nonstandard sunglasses regarding UVA transmission had graduated tints. 8.7% of graduated tints and 1.45% of smoky tints regarding UVB transmission did not meet the ANSI standards. Conclusion: Although a number of sunglasses presented by miscellaneous vendors were not standard, but in cases that it is not possible to buy expensive sunglasses, it is advisable to use inexpensive ones with nongraduated tints for eye protection against UVR for daily and non-industrial use.