Biological effects of high-energy visible light

High-energy visible light (HEV light) is high-frequency, high-energy light in the violet/blue band from 400 to 450 nm in the visible spectrum, which has a number of biological effects, including those on the eye. HEV light may be a cause of age-related macular degeneration. Some sunglasses and beauty creams specifically block HEV, for added marketing value. Currently, a 2019 report by France's Agency for Food, Environmental and Occupational Health & Safety (ANSES) supports the 2010 result on the adverse effect of blue LED light (400-450 nm spike) on the eye, which can lead to impaired vision. It highlights short-term effects on the retina linked to intense exposure to blue LED light, and long-term effects linked to the onset of age-related macular degeneration. Although few studies have examined occupational causes of macular degeneration, they show that long-term sunlight exposure, specifically its blue-light component, is associated with macular degeneration in outdoor workers. Harvard Health Publishing additionally asserts that exposure to blue light (especially blue LED light, but also broad-spectrum blue light) at night has a stronger negative effect on sleep. A June 14, 2016 press release by the American Medical Association concludes that there are negative health impacts from the unrestrained use of LED street lighting in general. Lenses that block blue light may be particularly useful for people with insomnia, bipolar disorder, delayed sleep phase disorder, or ADHD, though less beneficial for healthy sleepers. Blue light is a range of the visible light spectrum, defined as having a wavelength between 400 and 525 nm. This includes wavelengths between violet and cyan in the spectrum. Narrow-spectrum blue light (also called blue LED light or short-wavelength LED light) is a type of high-energy visible light, defined as having a wavelength between 400 and 450 nm. This light is common in LEDs (even when used in illumination products) as a carry-over from computer-screen technology. Blue light is an essential component of white light.