Blue light-blocking efficiency of blue light-blocking and driving spectacle lenses

Background: Retinal damage caused by blue light can result in glare, decreased visual acuity, and accelerated macular degeneration. In clinical practice, blue light-blocking glasses, such as driving glasses, are used to block blue light effectively. This study was aimed at measuring light transmittance to analyze the blue light-blocking efficiencies of blue light-blocking and driving spectacle lenses manufactured with tinting, coating, and only materials and at distinguishing the difference between the two spectacle lenses.   Methods: Blue light-blocking and driving spectacle lenses used to measure light transmittance were manufactured with tinting (blue light blocking lenses by tinting or “BTL” and driving spectacle lenses by tinting or “DTL,” respectively), coating (blue light blocking lenses by coating or “BCL” and driving spectacle lenses by coating or “DCL,” respectively), and only materials (blue light blocking lenses by material or “BML” and driving spectacle lenses by material or “DML,” respectively).   Results: Compared to BTL, DTL had a significantly greater decrease in the light transmission efficiency for visible and blue lights (P < 0.05). The blue light hazard function was lower for BML and DML than for conventional coating lenses in both visible and blue lights, although without significant differences between visible and blue lights (P > 0.05).   Conclusions: The blue light-blocking spectacle lenses had the highest blue light-blocking efficiency when manufactured with tinting, coating, and only materials, in order. With DML, the blue light-blocking efficiency was lower compared to DTL but higher compared to DCL. Therefore, DML could provide a balanced glare control and clear retinal image overall.