High-energy visible light

In ophthalmology, high-energy visible light (HEV light) is high-frequency light in the violet/blue band from 380 to 500 nm in the visible spectrum. HEV light has been implicated as a cause of age-related macular degeneration.

Some sunglasses are now designed specifically to block HEV.

Blue-light hazard

Blue-light hazard is defined as the potential for a photochemical induced retinal injury resulting from radiation exposure at wavelengths primarily between 400 nm and 500 nm. This has not been shown to occur in humans, only inconclusively in some rodent and primate studies (also a lack of authoritative references, and quantifying the conditions used) 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.^{[citation needed]}

See also

• Fluorescent lamps and health
• Ultraviolet light

External links

• Hanlin, Pete (2004). "The Effects of Visible Light and UVR on the Visual System". Review of Optometry. http://www.revoptom.com/. 
• "Artificial Lighting and the Blue Light Hazard (The Facts About Lighting and Vision)". MD Support Online Library. http://www.mdsupport.org/library/hazard.html. 
• Koide R, Ueda TN, Dawson WW, et al. (October 2001). "[Retinal hazard from blue light emitting diode]" (in Japanese). Nippon Ganka Gakkai Zasshi 105 (10): 687–95. PMID 11692615.