Everything You Need To Know About Heterochromia: Types, Causes & Rarity
The word heterochromia originates from Ancient Greece and means different (heteros) color (chroma). Heterochromia is the condition where the iris (the thin circular structure surrounding the pupil-its role is to control the amount of light reaching the retina) of each eye are differently colored. Heterochromia also exists for the hair and skin. Other terms to describe heterochromia of the iris include heterochromia iridis and heterochromia iridium). There are three types of heterochromia of the iris: complete heterochromia, segmental or sectoral heterochromia, and central heterochromia.
The Three Types Of Heterochromia In Human Eyes
Complete heterochromia is where one iris is completely different in color from the iris of the other eye. Segmental or sectoral heterochromia is where a part of the iris of one or both eyes is distinguished in color from the rest of the iris of that eye. Central heterochromia is distinguished by a different color on the iris at the border of the pupil with spikes of that color radiating outward toward the center of the iris. Celebrities with notable heterochromia include Max Scherzer, Josh Henderson (complete heterochromia); Kate Bosworth, Elizabeth Berkley and Henry Cavill (partial heterochromia); and Paris Hilton, Terrence Howard and Olivia Wilde (central heterochromia). The condition is not restricted to humans, but appears in many other animals as well Venus the Cat has acquired over a million followers on Instagram because of her unique look!
The Causes Of Heterochromia In Human Eyes
The color of the irides develop during the first few months after birth. The levels of the pigment melanin determine how dark the irides will become. The less melanin expressed, the lighter the color of the irides, and vice versa. When the concentration and distribution of melanin are inconsistent, the resulting condition is heterochromia. Most people with heterochromia are born with the condition, which is usually inherited. The condition may also result from a genetic mutation during embryonic development, and sometimes, heterochromia is a symptom of another condition. Horner’s syndrome results when a group of nerves called the sympathetic trunk is damaged and is an example of a condition that causes heterochromia. Waardenburg syndrome is another cause.
