Two different colored eyes in an animal or person is the result of a condition in which one eye has more or less melanin (pigment) than the other. Known as heterochromia, this condition can also exist in a partial stage, in which a particular section of one iris is different in color than the rest. All types of heterochromia, according to ultimatehealthguide.com, can be found in people, and in animals, as it is commonly seen in cats and dogs. The pigment affected by this condition is only in the iris (the colored part of the eye).
Two Different Colored Eyes Condition: Full Heterochromia
Full, or complete heterochromia is when the iris of one eye (of the two eyes of a creature) is a different color from that of the other eye. For instance, someone, or some animal with one blue eye and one brown eye would have full heterochromia. This condition may be genetic, and retained from birth, or it may be acquired, often by injury, in both humans and animals. Differences in the amount of melanin in eyes are usually the result of eyes that are different colors or shades. This type (the full or complete type) is known as heterochromia iridium.
Partial or Sectoral Heterochromia: Sections of Eyes Different Colors
This condition is fairly rare, and it results in certain parts of a single eye's iris being different colors from the rest of that iris. Known as heterochromia iridis, this may be represented by clouds of an offcolor hue in one eye, or by bands or sections of the iris in an eye being different colors, or different shades of the same color. Sometimes it appears as if certain rings of the iris are darker or lighter than the surrounding parts in people and animals that exhibit partial heterochromia. It is thought that this type of the condition may be attributable to other conditions.
Heterochromia in Animals
Although people may have this condition, it is very prevalent in certain types of animals. Cats and dogs, in particular, can be prone to heterochromia, and certain breeds may be more likely to have different colored eyes (within a single specimen) than others. One example of an animal (breed of dog) that very commonly exhibits heterochromia is the old English Sheepdog. These sheepdogs often have one eye much lighter than the other, or one blue eye and one brown eye. Domestic cats are also often seen with different colored eyes, as are horses.
Heterochromia is usually harmless, and simply the result of different levels of pigment in eyes. It may be found in people, and in some animals, usually appearing in the form of two different colored eyes in a single specimen, though the rarer type may designate different colors or shades within a single eye's iris.
 |
