Editing Color blindness (section)

===Lenses===
{{main|Color blind glasses}}

There are three kinds of lenses that an individual can wear that can increase their accuracy in some color related tasks (although none of these will "''fix''" color blindness or grant the wearer normal color vision):

* A red-tint contact lens worn over the non-dominant eye will leverage [[binocular disparity]] to improve discrimination of some colors. However, it can make other colors more difficult to distinguish. A 1981 review of various studies to evaluate the effect of the X-chrom (one brand) contact lens concluded that, while the lens may allow the wearer to achieve a better score on certain color vision tests, it did not correct color vision in the natural environment.<ref>{{cite journal | vauthors = Siegel IM | title = The X-Chrom lens. On seeing red | journal = Survey of Ophthalmology | volume = 25 | issue = 5 | pages = 312–24 | year = 1981 | pmid = 6971497 | doi = 10.1016/S0039-6257(81)80001-X }}</ref> A case history using the X-Chrom lens for a rod monochromat is reported<ref>{{cite journal | vauthors = Zeltzer HI | title = Use of modified X-Chrom for relief of light dazzlement and color blindness of a rod monochromat | journal = Journal of the American Optometric Association | volume = 50 | issue = 7 | pages = 813–8 | date = July 1979 | pmid = 315420 }}</ref> and an X-Chrom manual is online.<ref>[https://artoptical.com/lenses/special-lens-designs/x-chrom/ An X-Chrom manual] {{webarchive|url=https://web.archive.org/web/20150412155316/https://artoptical.com/lenses/special-lens-designs/x-chrom/ |date=2015-04-12 }}. Artoptical.com. Retrieved on 2016-12-10.</ref>
* Tinted glasses (e.g. Pilestone/Colorlite glasses) apply a tint (e.g. magenta) to incoming light that can distort colors in a way that makes some color tasks easier to complete. These glasses can circumvent many [[color vision test]]s, though this is typically not allowed.<ref name=FAA>{{cite journal |last1=Welsh |first1=Kenneth W |title=Aeromedical implications of the X-chrom lens for improving color vision deficiencies |journal=Aviation, Space, and Environmental Medicine |date=April 1978 |volume=50 |issue=3 |pages=249–255 |publisher=Federal Aviation Administration |location=Oklahoma City |pmid=313209 |url=https://pubmed.ncbi.nlm.nih.gov/313209/ |access-date=30 September 2022 |archive-date=30 September 2022 |archive-url=https://web.archive.org/web/20220930150022/https://pubmed.ncbi.nlm.nih.gov/313209/ |url-status=live }}</ref>
* Glasses with a [[notch filter]] (e.g. [[EnChroma]] glasses) filter a narrow band of light that excites both the L and M cones (yellow–green wavelengths).<ref>{{cite web|last1=Zhou|first1=Li|title=A Scientist Accidentally Developed Sunglasses That Could Correct Color Blindness|url=http://www.smithsonianmag.com/innovation/scientist-accidentally-developed-sunglasses-that-could-correct-color-blindness-180954456/?no-ist|website=Smithsonian|access-date=6 January 2018|language=en|archive-date=3 September 2017|archive-url=https://web.archive.org/web/20170903071849/http://www.smithsonianmag.com/innovation/scientist-accidentally-developed-sunglasses-that-could-correct-color-blindness-180954456/?no-ist|url-status=live}}</ref> When combined with an additional stopband in the short wavelength (blue) region, these lenses ''may'' constitute a [[neutral-density filter]] (have no color tint). They improve on the other lens types by causing less distortion of colors and will essentially increase the saturation of some colors. They will only work on trichromats (anomalous or normal), and unlike the other types, do not have a significant effect on Dichromats. The glasses do not significantly increase one's ability on color blind tests.<ref name="Robledo" />