Light is perceived through the retina, the light-sensing tissue layer of the eye, and can directly influence the brain. Light exposure triggers various biological responses that improve sleep quality and stabilize mood. Recently, violet light, exhibiting a unique wavelength of 360-400 nm, has garnered significant attention due to its perception through a specific receptor, marking a novel research area. Herein, we used "violet light glasses" that directly emit violet light into the human eye and investigated their effects on healthy humans in real-life settings. This study demonstrated that two hours of violet light exposure in the morning enhanced sleep quality in approximately 20% of the healthy participants and was also associated with improved blood glucose levels. Although this was a pilot study due to its small sample size, our findings indicate that violet light could potentially promote health benefits in humans.
Copyright: © 2025 Kato, Mitsukura. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.