Editing Eye color (section)

=== Special cases ===
==== Two different colors ====
[[File:Heterochromia_Iridis.jpg|thumb|Two different eye colors are known as [[heterochromia iridum]]]]
As a result of [[heterochromia iridum]], it is also possible to have two different eye colors. This occurs in humans and certain breeds of domesticated animals and affects less than 1 percent of the world's population.<ref name=":3" />

====Red and violet====
[[File:OCA1 Auge.jpg|thumb|Red-appearing albino eyes]]
The eyes of people with severe forms of [[albinism in humans|albinism]] may appear red under certain lighting conditions owing to the extremely low quantities of [[melanin]],<ref name="albinism">[http://www.albinism.org/publications/what_is_albinism.html NOAH – What is Albinism?] {{webarchive|url=https://web.archive.org/web/20120514003907/http://albinism.org/publications/what_is_albinism.html |date=14 May 2012 }}. Albinism.org. Retrieved on 23 December 2011.</ref> allowing the blood vessels to show through. In addition, [[flash photography]] can sometimes cause a "[[red-eye effect]]", in which the very bright light from a flash reflects off the retina, which is abundantly vascular, causing the pupil to appear red in the photograph.<ref>
{{cite news |title=HOW TO: Avoid the red eye effect |author=Dave Johnson |newspaper=[[PC World (magazine)#Countries|New Zealand PC World]] |date=16 January 2009 |url=http://pcworld.co.nz/pcworld/pcw.nsf/digi/D193D7DD8DD78628CC257540000F4A4F |access-date=9 January 2010 |archive-url=https://web.archive.org/web/20100224065704/http://pcworld.co.nz/pcworld/pcw.nsf/digi/D193D7DD8DD78628CC257540000F4A4F |archive-date=24 February 2010 }}
</ref>

Although the deep blue eyes of some people such as [[Elizabeth Taylor]] can appear purple or violet at certain times, "true" violet-colored eyes occur only due to albinism.<ref name="palmer20110325">{{cite web |url=http://www.slate.com/blogs/blogs/browbeat/archive/2011/03/25/elizabeth-taylor-beautiful-mutant.aspx |archive-url=https://web.archive.org/web/20110327113617/http://www.slate.com/blogs/blogs/browbeat/archive/2011/03/25/elizabeth-taylor-beautiful-mutant.aspx |archive-date=27 March 2011 |title=Elizabeth Taylor: Beautiful Mutant |access-date=26 March 2011 |author=Palmer, Roxanne |date=25 March 2005 |work=Slate}}</ref><ref name="Albinism">{{cite encyclopedia |last1=Fertl |first1=Dagmar |last2=Rosel |first2=Patricia |title=Albinism |encyclopedia=Encyclopedia of Marine Mammals |edition=Second |entry=Albinism |publisher=Academic Press |date=2009 |pages=24–26 |doi=10.1016/b978-0-12-373553-9.00006-7 |isbn=978-0-12-373553-9 |entry-url=https://www.sciencedirect.com/science/article/pii/B9780123735539000067 |access-date=11 October 2022}}</ref><ref>{{cite journal |last1=White |first1=Désirée |last2=Rabago-Smith |first2=Montserrat |title=Genotype–phenotype associations and human eye color |journal=Journal of Human Genetics |date=2010 |volume=56 |issue=1 |pages=5–7 |doi=10.1038/jhg.2010.126 |pmid=20944644 |s2cid=33808164 |doi-access=free }}</ref> Eyes that appear red or violet under certain conditions due to albinism occur in less than 1 percent of the world's population.<ref name=":3">{{Cite web|title=The World's Population By Eye Color|url=https://www.worldatlas.com/articles/which-eye-color-is-the-most-common-in-the-world.html|access-date=2021-05-10|website=WorldAtlas|date=6 October 2020|language=en-US}}</ref>