High-energy Visible Light - Blue-light Hazard

Blue-light hazard is defined as the potential for a photochemical induced retinal injury resulting from electromagnetic radiation exposure at wavelengths primarily between 400 - 500 nm. This has not been shown to occur in humans, only inconclusively in some rodent and primate studies. The mechanisms for photochemical induced retinal injury are caused by the absorption of light by photoreceptors in the eye. Under normal conditions when light hits a photoreceptor, the cell bleaches and becomes useless until it has recovered through a metabolic process called the visual cycle. Absorption of blue light, however, has been shown to cause a reversal of the process where cells become unbleached and responsive again to light before they are ready. This greatly increases the potential for oxidative damage. By this mechanism, some biological tissues such as skin, the lens of the eye, and in particular the retina may show irreversible changes induced by prolonged exposure to moderate levels of UV radiation and short-wavelength light.