Complete Heterochromia Iridium
Heterochromia Iridium is the presence of two eyes which present with a different colored iris. This disorder can be sectoral or complete. Sectoral heterochromia iridium is when both eyes have two different colors in each eye. Complete heterochromia iridium is when both eyes have only one color each.
Heterochromia Iridium can be seen in cats, dogs, and humans. Heterochromia iridium is more commonly seen in white female cats than any other animal and color combination.
Sectoral Heterochromia Iridium
How Is Heterochromia Iridium Caused?
The color of the eye is usually determined by a pigment called melanin in both cats and humans. This pigment is determined by genetics. White cats usually have odd eyes because of the white spotting gene or the white gene which prevents melanin granules from reaching one eye during their development.
In cats that do not have the white spotting gene or the white spot gene, this condition is considered extremely rare. The white spotting gene which affects color as the dominant white gene, often ends up masking the other genes in order to make the cat completely white.
Odd-Eyed Cat History And Rarity
Breeds such as the Turkish Angora and Turkish Van are much more likely to develop heterochromia iridium than other breeds of cats. Cats that have two different colored eyes are often referred to as an odd eyed cat. The rarest cat to see with two odd colored eyes is black or tortoiseshell.
White cats that have two different colored eyes are still quite rare. Only about 1 in 1000 cats is likely to have this condition according to recent shelter statistics. Turkish Angora cats with blue and amber eyes are a treasure in Turkey because of their rarity. People cherished these cats because they wanted them to have a blue eye that was as blue as the sky and green eyes that were as green as the lake.
Venus is a “Chimera Cat” who is half-orange and half-black, in addition to having complete heterochromia iridium. This cat is one of a kind and was once thought to be a fake cat until the owner proved her history with pictures she has taken of her.