Heterochromia – An Eye of a Different Colour

We are used to people having different eye colours, brown, blue, green, hazel, etc. We may even have seen someone whose eye colour appears to change, depending on lighting. But have you ever met someone who has two distinct different eye colours? Have you ever wondered what may cause something like that to happen?

What is Heterochromia?

Much like regular eye colour, Heterochromia is caused by Melanin, a pigment that affects your hair skin and eye colour. The more melanin there is in the iris of your eye, the darker the colour. In most cases, the more melanin in your skin and hair, the more likely you are to be brown eyed. But, as we know, there are exceptions to every rule. In the case of heterochromia, the melanin does not affect the eyes equally, either with one eye becoming noticeably darker than the other, or with one part of the iris darker than the other, creating the appearance of two colours in the same eye. Heterochromia can be inherited from your parents or grandparents, or it may appear randomly. It is very rare, and usually has no effect on your vision, but once again, there are exceptions.

Types of Heterochromia

There are several different types of heterochromia:
Complete Heterochromia or Heterochromia Iridium describes a condition where people have two different coloured eyes, i.e.) One blue eye and one brown eye. It is quite rare, although celebrities who have it include actors: Jane Seymour, Mila Kunis, Josh Henderson and Alice Eve.
Partial Heterochromia or Heterochromia Iridis is a condition where a person will have two different colours in the same iris of the eye.  It is much more common than Complete Heterochromia and can be further broken down into:
Central Heterochromia, where the inner part of the iris is one colour, with a ring of another colour around it. Actors who have central heterochromia include: Christopher Walken, Idina Menzel and Olivia Wilde.
Sectorial Heterochromia also involves two colours within the same eye, but instead of an inner and outer ring of differing colours, the iris is mostly one colour with a different colour spot or blotch on it. Celebrities with sectorial heterochromia include Kate Bosworth, Elizabeth Berkley and Henry Cavill (That’s right, Superman has two different eye colours).

Should I worry if I have Heterochromia?

If you are born with a type of Heterochromia, it is unlikely that it will lead to any serious complications. But, rare as the condition may be, it has occasionally been connected with conditions such as Bloch-Sulzberger syndrome, Bourneville disease, Hirschsprung disease, Horner’s syndrome, Parry-Romberg syndrome, Sturge-Weber syndrome, Von Recklinghausen disease and Waadenburg syndrome. On the other hand, if you develop heterochromia later in life, it could be a warning of other conditions you need to be aware of. Acquired Heterochromia has been known to be caused by diabetes, glaucoma, eye injuries, Iris Ectropion syndrome, Pigment Dispersion syndrome, Posner-Schlossman syndrome and eye tumors. In any case, if you have concerns about your eyes, or if you have noticed any changes, contact your optometrist immediately.  Don’t take chances with your vision.