Heterochromia is a Greek word for differences in iris, skin and hair color.Heteros means different and chroma means color. People who have this usually have one iris that is a different color, lighter or darker than the other iris. This is caused by too much or too little melanin or pigmentation. The underlying causes include; disease, eye injury, genetic chimerism or mosaicism (a living organism that has two genetically different sets of cells in their body).
Heterochromia is a rare condition only affecting about 11 people per 1,000 in the United States. Beside central heterochromia, there are two other types of heterochromia. This article explains what the eye color is like in all conditions.
Types of Heterochromia
Heterochromia manifests itself in one of three different types; central, sectoral and complete. It is also looked at by how the onset occurred; acquired or genetic. While most cases of this condition are genetic, there are some instances that an eye changes color because of an underlying condition or an injury to the eye. Let’s take a quick look at the breakdown of these different types:
Central Heterochromia
Take a closer look at this intriguing example where the center of the iris is gold and the outer or “true eye color” is blue. Often referred to as “cat eyes,” this type is manifested by the appearance of two different colors in one iris. One color occupies the central part of the iris and the outer edge is a different color. The “true” eye color is always the outside color of the iris. Watch this exciting video on a case:
Sectoral and Complete Heterochromia
Sectoral Heterochromia
With Sectoral Heterochromia, the iris contains two completely different colors in the same area. Sectoral Heterochromia looks like an irregular spot that is a different color than the eye color and does not form a complete ring around the pupil. Here is a video about Sectoral Heterochromia:
Complete Heterochromia
Complete Heterochromia occurs when the eyes are of two different colors. This is the most dramatic of all the Heterochromia. Someone may have one blue eye and one green eye or a blue eye and a brown eye. Complete Heterochromia is also common in animals, below are complete heterochromia manifested in both human and animals:
