Quality of sunglasses available in the Iranian market; a study with emphasis on sellers’ license.

Context: Sunglasses should follow minimum requirements to sufficiently protect eyes. It is not known whether all items obtainable from the market are appropriately designed. Aims: To compare ultraviolet (UV)‑protective properties of commercially available sunglasses obtained from authorized and unauthorized Iranian sellers. Settings and Study Design: An analytic‑descriptive study performed in a metropolitan area (Tehran). Materials and Methods: Using a UV‑visible standard spectrophotometer, the percentage transmittance was scanned between 280 and 400 nm in 348 pairs of nonprescription sunglasses (price range: 20–80 US$) obtained anonymously and randomly from authorized (permitted by the Ministry of Health, 189 pairs) and unauthorized (159 pairs) sellers in the Iranian capital city, Tehran. The Australian/New Zealand Standard (AS/NZS) and the American National Standards Institute [ANSI] standards were followed. Statistical Analysis: Chi‑square test, independent samples t‑test or Mann–Whitney U‑test. Results UV‑protective properties of the sunglasses obtained from authorized sellers complied with AS/NZS and ANSI guidelines in 92.6% and 95.2% of items, respectively. The corresponding rates for sunglasses obtained from unauthorized sellers were 0% and 8.2%, respectively (P < 0.001 for both). The rate of defective polarizing capability of lenses was 27.4% in sunglasses obtained from authorized sellers versus 90.4% in sunglasses obtained from unauthorized sellers (P < 0.001). Neither brand nor price played significant contributions to UV protection/lens polarizing capability of sunglasses obtained from authorized sellers. Conclusions: Sunglasses provided by unauthorized sellers are alarmingly unreliable and could be potentially hazardous for the eye. Brand and price do not guarantee optimal protection against UV radiation or polarizing performance of the lens.

UV Protection Effect of Commonly Used Sunglasses and Guideline for Selecting Sunglasses

Although it is well known that ultraviolet and short wavelength visible rays are harmful to the human lens and the retina, consumers still tend to select sunglasses on the basis of fashion rather than protective quality. In order to provide guidelines for selecting appropriate sunglasses, we studied the mechanism of phototoxic damage and UV protective quality of commonly used sunglasses. Commonly used sunglasses were chosen by random sampling, and their UV transmittance was examined by spectrophotometer using neutral density filter method. UV transmittance was shown to be 3.0% to 40.8% and there was no significant relationship between UV transmittance and the tint or darkness of the sunglasses.