Editing Sunglasses (section)

== Special-use ==

=== Land vehicle driving ===
[[File:Hst-by-rsexton-longbeach-5-1989-1.jpg|thumb|right|[[Hunter S. Thompson]] was known for wearing yellow-tinted driving glasses.]] When driving a vehicle, particularly at high speed, dazzling glare caused by a low Sun, or by lights reflecting off snow, puddles, other vehicles, or even the front of the vehicle, can be lethal. Sunglasses can protect against glare when driving. Two criteria must be met: vision must be clear, and the glasses must let sufficient light get to the eyes for the driving conditions. General-purpose sunglasses may be too dark, or otherwise unsuitable for driving.

[[The Automobile Association]] and the [[Federation of Manufacturing Opticians]] have produced guidance for selection of sunglasses for driving. Variable tint or photochromic lenses increase their optical density when exposed to UV light, reverting to their clear state when the UV brightness decreases.  Car windscreens filter out UV light,<ref>[https://www.theglobeandmail.com/globe-drive/culture/commuting/does-my-windshield-protect-me-from-the-sun/article12495123/ The Globe and Mail] {{webarchive|url=https://web.archive.org/web/20170406201410/http://www.theglobeandmail.com/globe-drive/culture/commuting/does-my-windshield-protect-me-from-the-sun/article12495123/ |date=2017-04-06 }}, "Does my windshield protect me from the sun?", retrieved 6 April 2017</ref><ref>{{cite web|url=http://www.autoblog.com/2013/09/06/not-all-car-windows-protect-against-uv-rays/|title=Not All Car Windows Protect Against UV Rays|website=autoblog.com|date=6 September 2013 |access-date=6 April 2017|url-status=live|archive-url=https://web.archive.org/web/20170406201538/http://www.autoblog.com/2013/09/06/not-all-car-windows-protect-against-uv-rays/|archive-date=6 April 2017}}</ref> slowing and limiting the reaction of the lenses and making them unsuitable for driving as they could become too dark or too light for the conditions. Some manufacturers produce special photochromic lenses that adapt to the varying light conditions when driving.

Lenses of fixed tint are graded according to the optical density of the tint; in the UK sunglasses must be labelled and show the filter category number. Lenses with light transmission less than 75% are unsuitable for night driving, and lenses with light transmission less than 8% (category 4) are unsuitable for driving at any time; they should by UK law be labelled 'Not suitable for driving and road use'. Yellow tinted lenses are also not recommended for night use. Due to the light levels within the car, filter category 2 lenses which transmit between 18% and 43% of light are recommended for daytime driving. Polarised lenses normally have a fixed tint, and can reduce reflected glare more than non-polarised lenses of the same density, particularly on wet roads.

Graduated lenses, with the bottom part lighter than the top, can make it easier to see the controls within the car. All sunglasses should be marked as meeting the standard for the region where sold. An [[anti-reflection coating]] is recommended, and a hard coating to protect the lenses from scratches. Sunglasses with deep side arms can block side, or peripheral, vision and are not recommended for driving.<ref>{{Cite web|url=https://www.theaa.com/about-us/public-affairs|archive-url=https://web.archive.org/web/20160415211919/http://www.theaa.com/public_affairs/reports/driving-in-sunglasses.html|url-status=dead|title=Public affairs &#124; AA|archive-date=April 15, 2016|website=www.theaa.com|access-date=Jun 24, 2020}}</ref><!--ref for all the vehicle section-->

Even though some of these glasses are proven good enough for driving at night, it is strongly recommended not to do so, due to the changes in a wide variety of light intensities, especially while using yellow tinted protection glasses. The main purpose of these glasses are to protect the wearer from dust and smog particles entering into the eyes while driving at high speeds.

=== Aircraft piloting ===
Many of the criteria for sunglasses worn when piloting an aircraft are similar to those for land vehicles. Protection against UV radiation is more important, as its intensity increases with altitude. Polarised glasses are undesirable as aircraft windscreens are often polarised, intentionally or unintentionally, showing [[Moiré pattern]]s on looking through the windscreen; and some [[LCD]]s used by instruments emit polarised light, and can dim or disappear when the pilot turns to look at them.

=== Sports ===
[[File:Water sunglasses kayaker.jpg|thumb|Sunglasses worn by an [[Ocean kayaking|ocean kayaker]]]]
[[File:Sona Sherpa on expedition to K2 in winter (cropped).jpg|thumb|A [[Sherpa people|Sherpa]] [[mountain guide]] on an expedition to [[K2]] (8.611 m), wearing anatomically shaped mountaineering sunglasses]]
{{Anchor|Strap}}Like [[corrective lens|corrective glasses]], sunglasses have to meet special requirements when worn for sports. They need shatterproof and impact-resistant lenses; a strap or other fixing is typically used to keep glasses in place during sporting activities, and they have a nose cushion.<ref>{{Cite web |date=2022-11-01 |title=Sports Glasses vs. Regular Glasses |url=https://www.libertysport.com/viewpoint/sports-glasses-vs-regular-glasses/ |access-date=2023-12-28 |website=Viewpoint |language=en}}</ref>

For water sports, so-called water sunglasses (also: surf [[goggles]] or water eyewear) are specially adapted for use in turbulent water, such as the [[Breaking wave|surf]] or [[whitewater]]. In addition to the features for sports glasses, water sunglasses can have increased [[buoyancy]] to stop them from sinking should they come off, and they can have a vent or other method to eliminate fogging.<ref>{{Cite web |title=Goggles {{!}} Definition, Purpose, Types, & Facts {{!}} Britannica |url=https://www.britannica.com/technology/goggles |access-date=2023-12-28 |website=www.britannica.com |language=en}}</ref>

Mountain climbing or traveling across glaciers or snowfields requires above-average eye protection, because sunlight (including ultraviolet radiation) is more intense in higher altitudes, and snow and ice reflect additional light. Popular glasses for this use are a type called '''glacier glasses''' or '''glacier [[goggles]]'''. They typically have very dark round lenses and leather blinders at the sides, which protect the eyes by blocking the Sun's rays around the edges of the lenses. [https://www.alpineascents.com/blog/gear/what-are-glacier-glasses/ What are Glacier Glasses?]

Special shaded visors were once allowed in [[American football]]; [[Jim McMahon]], quarterback for the [[Chicago Bears]] and [[San Diego Chargers]], famously used a sun visor during his professional football career due to a childhood eye injury and almost always wears dark sunglasses when not wearing a [[football helmet]]. Darkened visors now require a doctor's prescription at most levels of the game, mainly because concussion protocol requires officials to look a player in the eye, something made difficult by tinted visors.<ref>{{cite web|url=http://www.livestrong.com/article/104516-purpose-football-helmet-visor/ |title=What is the Purpose of a Football Helmet Visor? &#124; LIVESTRONG.COM |access-date=2016-09-17 |url-status=live |archive-url=https://web.archive.org/web/20160919012153/http://www.livestrong.com/article/104516-purpose-football-helmet-visor/ |archive-date=2016-09-19 }}</ref>

<gallery>
Seal Swim Goggles.jpg|Swimming goggles
Mezmay, Sports sunglasses, Russia.jpg|Sports sunglasses for mountain climbing and hiking
</gallery>

=== Space ===
[[File:STS-116 Fuglesang EVA2 (ISS014-E-09795) head.jpg|thumb|2006: Swedish astronaut [[Christer Fuglesang]] wears glasses during a construction mission for the [[International Space Station]].]] Special protection is required for space travel because the sunlight is far more intense and harmful than on Earth, where it is always filtered through the [[atmosphere]]. Sun protection is needed against much higher UV radiation and even against harmful [[infrared]] radiation, both within and outside the spacecraft. Within the spacecraft, astronauts wear sunglasses with darker lenses and a thin protective [[gold]] coating. During [[space walk]]s, the visor of the astronauts' helmets, which also has a thin gold coating for extra protection, functions as strong sunglasses.<ref name="NASA glasses">{{usurped|1=[https://web.archive.org/web/20021104204751/http://www.sti.nasa.gov/tto/spinoff2002/ch_2.html ''no author'' (''no date''). Spinoff 2002. Space-Age Shades. ''Scientific and Technical Information (STI)'' on the]}} [[NASA]] website (retrieved on 21 September 2009)</ref><ref>{{cite web |url=http://www.silhouette-international.com/silhouette/press/meilensteine_eng.doc |title=Archived copy |access-date=2009-09-22 |url-status=dead |archive-url=https://web.archive.org/web/20130514115437/http://www.silhouette-international.com/silhouette/press/meilensteine_eng.doc |archive-date=2013-05-14 }}</ref><ref>{{cite web|author=Optikum, Unabhängiges Augenoptik-Panorama|url=http://www.optikum.at/469.htm|title=optikum, UNABHÄNGIGES AUGENOPTIK-PANORAMA – Silhouette Titan Minimal Art Space Edition – Die leichteste Brille des Universums|publisher=Optikum.at|access-date=2010-05-13|url-status=dead|archive-url=https://web.archive.org/web/20100428091442/http://www.optikum.at/469.htm|archive-date=2010-04-28}}</ref> The frames of sunglasses and corrective glasses used in space must meet special requirements. They must be flexible and durable, and must fit firmly in zero-gravity. Reliable fit is particularly important when wearing corrective glasses underneath tight helmets and in space suits: once inside the spacesuit, slipped glasses cannot be touched to push them back into place, sometimes for up to ten hours. Frames and glasses must be designed so that small pieces of the glasses such as screws and glass particles cannot become dislodged, then float and be inhaled. 90% of astronauts wear glasses in space, even if they do not require corrective glasses on Earth, because zero-gravity and pressure changes temporarily affect their vision.<ref name="NASA glasses" />

The first sunglasses used in a Moon landing were the original [[#Aviator|pilot sunglasses]] produced by [[American Optical Company|American Optical]]. In 1969 they were used aboard the ''Eagle'', the [[Apollo Lunar Module|Lunar Module]] of [[Apollo 11]], the first crewed mission to land on the Moon.<ref>{{cite web|url=http://www.aaapilots.com/html/american_optical_aviator_sungl.html |archive-url=https://web.archive.org/web/20070521174037/http://www.aaapilots.com/html/american_optical_aviator_sungl.html |url-status=usurped |archive-date=2007-05-21 |title=''no author'' (''no date''). American Optical Flight Gear Vintage Sunglasses. on ''AAA Pilot Supplies'' (retrieved on 21 September 2009) |publisher=Aaapilots.com |date=1969-07-20 |access-date=2010-05-13 }}</ref> NASA research primarily by scientists James B. Stephens and Charles G. Miller at the [[Jet Propulsion Laboratory]] (JPL) resulted in special lenses that protected against the light in space and during laser and [[welding]] work. The lenses used colored dyes and small particles of [[zinc oxide]], which absorbs ultraviolet light and is also used in [[sunscreen]] lotions. The research was later broadened to further terrestrial applications, ''e.g.'', deserts, mountains, and fluorescent-lighted offices, and the technology was commercially marketed by a U.S. company.<ref>[http://www.sti.nasa.gov/tto/Spinoff2006/ch_6.html ''no author'' (2006). Look Sharp While Seeing Sharp. (Originating Technology/NASA Contribution).] {{webarchive |url=https://web.archive.org/web/20120325015909/http://www.sti.nasa.gov/tto/Spinoff2006/ch_6.html |date=March 25, 2012 }} ''Spinoff 2006'', NASA Scientific and Technical Information (STI). Retrieved 17 October 2009.</ref> Since 2002 NASA uses the frame of the designer model ''Titan Minimal Art'' of the Austrian company [[Silhouette (eyewear)|Silhouette]], combined with specially dark lenses developed jointly by the company and "the" NASA [[optometrist]] Keith Manuel. The frame is very light at 1.8 grams, and does not have screws or hinges that could detach.<ref name="NASA glasses" />

<gallery>
 EdwinAldrin big.jpg|1969 on board the [[Apollo 11|Eagle]]: [[Buzz Aldrin]] stows his sunglasses before the Moon landing.
 Aldrin Apollo 11 head.jpg|1969: Helmet visor protecting [[Buzz Aldrin|Aldrin]]'s eyes on the Moon
</gallery>