Spectral transmission of commercially available high-energy visible light-filtering spectacle lenses.

Abstract

SIGNIFICANCE High-energy visible (HEV) light-filtering spectacle lenses are being widely promoted despite limited evidence to support their use. The spectral transmission properties of commercially available lenses varied, particularly in the HEV light region, and they do not perform in the same way for transmission of ultraviolet (UV)-A and HEV light. PURPOSE Although HEV light is important for several visual and nonvisual functions, there are concerns over the potential adverse effects of increased HEV light exposure. High-energy visible light-filtering spectacle lenses are being widely marketed to promote ocular health and improve sleep by reducing exposure to HEV light. This study reports on the spectral transmission characteristics of commercially available HEV light-filtering spectacle lenses based on the recommendations of the Spectral Bands Task Force technical report. METHODS The spectral transmission of light through nine afocal plastic lenses, including eight commercially available HEV light-filtering lenses and one clear uncoated control lens, was evaluated using a Cary 5000 UV-Vis-NIR spectrophotometer (Agilent Technologies, Johannesburg, South Africa) for wavelengths 250 to 780 nm. The percentage transmission values are reported for UV radiation and visible light, with emphasis for HEV light (380 to 500 nm) and the three subbands therein. RESULTS All lenses blocked UV-C and UV-B radiation (250 to 315 nm). For UV-A radiation (315 to 380 nm), six lenses showed optimal 100% absorption, whereas three lenses allowed ≤12%. The transmission values for the HEV light-filtering lenses ranged from 55 to 90% and 75 to 95% for HEV light of wavelengths 400 to 455 nm and 455 to 500 nm, respectively. In contrast, the control lens showed 92 (400 to 455 nm) and 93% (455 to 500 nm) transmission. CONCLUSIONS The HEV light-filtering spectacle lenses varied in their transmission properties and do not necessarily perform in the same way for transmission of UV-A and HEV light. Optometric personnel should consider these transmission properties, particularly for HEV light, when making recommendations to patients about HEV light-filtering spectacle lenses.