Editing Ultraviolet (section)

====Eye damage====
[[File:UV Warning.jpg|thumb|Signs are often used to warn of the hazard of strong UV sources.]]
The eye is most sensitive to damage by UV in the lower UVC band at 265–275&nbsp;nm. Radiation of this wavelength is almost absent from sunlight at the surface of the Earth but is emitted by artificial sources such as the [[electrical arcs]] employed in [[arc welding]]. Unprotected exposure to these sources can cause "welder's flash" or "arc eye" ([[photokeratitis]]) and can lead to [[cataract]]s, [[pterygium]] and [[pinguecula]] formation. To a lesser extent, UVB in sunlight from 310 to 280&nbsp;nm also causes photokeratitis ("snow blindness"), and the [[cornea]], the [[Lens (anatomy)|lens]], and the [[retina]] can be damaged.<ref>{{cite report |url=https://www.who.int/uv/faq/uvhealtfac/en/index3.html |title=The known health effects of UV |publisher=World Health Organization |url-status=live |archive-url=https://web.archive.org/web/20161024170159/http://www.who.int/uv/faq/uvhealtfac/en/index3.html |archive-date=24 October 2016}}</ref>

[[Protective eyewear]] is beneficial to those exposed to ultraviolet radiation. Since light can reach the eyes from the sides, full-coverage eye protection is usually warranted if there is an increased risk of exposure, as in high-altitude mountaineering. Mountaineers are exposed to higher-than-ordinary levels of UV radiation, both because there is less atmospheric filtering and because of reflection from snow and ice.<ref>{{cite web |url=https://www.who.int/uv/faq/whatisuv/en/index3.html |title=UV radiation |publisher=World Health Organization |url-status=live |archive-url=https://web.archive.org/web/20161025234856/http://www.who.int/uv/faq/whatisuv/en/index3.html |archive-date=25 October 2016}}</ref><ref>{{cite report |title=What is UV radiation and how much does it increase with altitude? |publisher=U.S. [[National Oceanographic and Atmospheric Administration]] |url=http://www.wrh.noaa.gov/fgz/science/uv.php?wfo=fgz |url-status=live |archive-url=https://web.archive.org/web/20170103102305/http://www.wrh.noaa.gov/fgz/science/uv.php?wfo=fgz |archive-date=3 January 2017}}</ref>
Ordinary, untreated [[eyeglasses]] give some protection. Most plastic lenses give more protection than glass lenses, because, as noted above, glass is transparent to UVA and the common acrylic plastic used for lenses is less so. Some plastic lens materials, such as [[polycarbonate]], inherently block most UV.<ref>{{cite web |url=https://www.opticianonline.net/features/optical-properties-of-lens-materials-2 |title=Optical properties of lens materials |website=Optician Online |date=6 June 2005 |url-access=subscription |url-status=live |archive-url=https://web.archive.org/web/20161026000953/https://www.opticianonline.net/features/optical-properties-of-lens-materials-2 |archive-date=26 October 2016}}</ref>