Protective properties of spectacle lenses used as ultraviolet blockers

Abstract

In this study, we evaluated the UV transmittance of spectacle lenses in the Turkish market, which are reported to have UV blocking properties, and tested their suitability. Samples were obtained from patients who were admitted to the ophthalmology outpatient clinic of our hospital for refractive error and who wore glasses as UV block. No limitation was made regarding the spectacle size and duration of spectacle wear. Measurements were tested by the principal investigator using an ultraviolet detector. The right and left lens were measured separately. All measurements were performed at room temperature (22-25°C) in a humidity regulated (20-40%) room without direct light. UV protection level was measured for 120 spectacles used for refractive errors. Only 28 (23.3%) of 120 glasses had protection level up to 400 nm UV. Twenty-four (20%) of the glasses had a protection level of 0 even though they were labeled as having UV blocking properties. It is clear that strict regulations need to be implemented to improve the protection levels of glasses.