Editing Color blindness (section)

====Blue–yellow color blindness====
Blue–yellow color blindness includes '''tritan''' CVD. Tritan CVD is related to the S-cone and includes tritanomaly (anomalous trichromacy) and tritanopia (dichromacy). Blue–yellow color blindness is much less common than red–green color blindness, and more often has acquired causes than genetic. Tritans have difficulty discerning between bluish and greenish hues.<ref>Steefel, Lorraine T., and Timothy E. Moore, PhD. "Color Blindness." ''The Gale Encyclopedia of Nursing and Allied Health'', edited by Jacqueline L. Longe, 4th ed., vol. 2, Gale, 2018, pp. 890–892. ''Gale eBooks'', Accessed 29 Dec. 2021.</ref> Tritans have a neutral point at 571&nbsp;nm (yellowish).<ref>{{Cite journal |last=Graham |first=C. H. |last2=Hsia |first2=Y. |date=1958-03-28 |title=Color defect and color theory; studies of normal and colorblind persons, including a subject color-blind in one eye but not in the other |url=https://pubmed.ncbi.nlm.nih.gov/13529033/ |journal=Science |volume=127 |issue=3300 |pages=675–682 |doi=10.1126/science.127.3300.675 |issn=0036-8075 |pmid=13529033}}</ref><ref>{{Cite web |title=SBFAQ Part 4: Color Blindness |url=https://visualexpert.com/Resources/cfaqPart4.html |access-date=2025-03-09 |website=visualexpert.com}}</ref>

{{anchor|Tritanopia}}
{{anchor|Tritanomaly}}
{{anchor|Tritan}}
* '''Tritan''' (<&nbsp;0.01% of individuals): Lacking, or possessing anomalous [[OPN1SW|S-opsins]] or short-wavelength sensitive cone cells. Tritans see short-wavelength colors ([[blue]], [[indigo]] and spectral [[Violet (color)|violet]]) as greenish and drastically dimmed, some of these colors even as [[black]]. Yellow and orange are indistinguishable from [[white]] and [[pink]] respectively, and purple colors are perceived as various [[shades of red]]. Unlike protans and deutans, the mutation for this color blindness is carried on chromosome 7. Therefore, it is not sex-linked (equally prevalent in both males and females). The OMIM gene code for this mutation is 304000 "Colorblindness, Partial Tritanomaly".<ref>{{cite web | title = Disease-causing Mutations and protein structure |url=http://www.biochem.ucl.ac.uk/bsm/humgen/chr__034.html#304000 | archive-url=https://web.archive.org/web/20050501081119/http://www.biochem.ucl.ac.uk/bsm/humgen/chr__034.html#304000 | url-status = dead | archive-date = 2005-05-01 | publisher = UCL Biochemistry BSM Group | access-date = 2007-04-02 }}</ref>
{{anchor|Tetartanopia}}
{{anchor|Tetartanomaly}}
{{anchor|Tetartan}}
* '''Tetartan''' is a hypothetical "fourth type" of color blindness, and a type of blue–yellow color blindness. Given the molecular basis of human color vision, it is unlikely this type could exist.<ref>{{Cite journal |last1=V |first1=Ionica |last2=Gastaud |first2=P |title=Test chromatique pour dépistage et étalonnage des dyschromatopsies |trans-title=Color vision test for detection and evaluation of dyschromatopsia |url=https://pubmed.ncbi.nlm.nih.gov/9033889/ |journal=Journal Français d'Ophtalmologie |date=1996 |language=fr |volume=19 |issue=11 |pages=679–688 |pmid=9033889 |access-date=13 June 2024 |archive-date=13 June 2024 |archive-url=https://web.archive.org/web/20240613193630/https://pubmed.ncbi.nlm.nih.gov/9033889/ |url-status=live }}</ref>