| Abstrakt: |
Purpose: High-energy visible light (commonly referred to as blue light) transmittance in sunglasses plays an important role in eye safety. Current standards do not have specific requirements for blue light ocular protection, as in the past. However, the literature has warned against potential harm to the eye caused by blue light. The limits imposed in the past state that the average spectral transmission in the 380–500 nm range should not be 20% in excess of the luminous transmittance in the 380–780 nm range. The literature on transmittance evaluations of blue-blocker sunglasses and their aging processes is scarce. Thus, in addition to the transmittance of blue light in sunglasses, this study investigates the limits of these transmittances before and after artificial aging of lenses in a solar simulator. Methods: Twelve sunglasses samples were artificially aged within a solar simulator for a period of 2500 h, which is compatible with a user wearing them for 2 h a day for 2 years. The spectral transmittances of the lenses were measured every 25 h to assess the time evolution of the blue-blocking protection of the lenses, as evaluated by current and old standards. Results: The results showed that there were relevant changes in the lenses over time; that is, they considerably weakened their blue light attenuation capabilities. Thus, during the aging process, some lenses exhibited increased blue light transmittance compared to the visible one, exceeding the 120% criterion established by a superseded standard. Conclusion: The results suggest that aging tests should be performed on sunglasses not only for ultraviolet radiation, as required by most standards, but also for blue light. Furthermore, the standards should include constraints on blue light attenuation. In the context of public health and preventive medicine, evaluation of blue blockers from various perspectives is of ongoing interest. |
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