Have you ever noticed an animal with two different colored eyes? This is pretty common in cats as about 60% have this condition but less common in dogs with only about 4%.

Animals aren’t the only ones with two different eye colors; humans can have it as well. Just over 1% of Americans have two different colored eyes. This condition is called heterochromia. There are three types of heterochromia:

  1. Complete Heterochromia – one iris is a different color from the other
  2. Partial Heterochromia or Sectoral Heterochromia – part of one iris is a different color from the rest of the iris
  3. Central Heterochromia – an inner ring is a different color than the rest of the iris

The concentration and distribution of melanin are what determines the eye color, specifically the color of the irises. The affected eye may be hyper pigmented (hyper chromic) or hypo pigmented (hypo chromic). The excess of melanin indicates hyperplasia of the iris tissues, whereas a lack of melanin indicates hypoplasia. In most cases this condition is hereditary, but this condition may also be caused by certain diseases or injury to the eye.

A few celebrities who have two different colored eyes include David Bowie, Christopher Walken, Dan Aykroyd, Jane Seymour, and Mila Kunis. If you happen to be a part of this special 1% group, then be sure to mark your calendar for July 12 as it happens to be National Different Colored Eyes Day. This is your day to open up your multi colored peepers and show them off.

Danielle Dilts, Human Resources Assistant