You’ve seen it before. Maybe in a mirror, or perhaps staring back at you from a high-resolution photo of Max Scherzer or the late, great David Bowie. One eye is a piercing blue, while the other is a deep, earthy brown. It’s striking. It’s rare. Honestly, it’s a bit of a genetic superpower in the looks department.
So, what is it called when you have different colored eyes? The technical term is heterochromia iridis.
Most people just call it heterochromia. It’s not a disease, usually. It’s basically just a quirk of melanin distribution within the iris. The iris is that colored ring around your pupil, and its hue is determined by how much pigment you’ve got packed in there. Think of it like paint. If one eye gets a double coat of "Deep Espresso" and the other only gets a light wash of "Sky Blue," you end up with that signature mismatched look.
The Different Flavors of Heterochromia
Not all mismatched eyes look the same. Scientists break it down into three main types because, as it turns out, there are several ways for your DNA to get creative with your face.
First, there’s complete heterochromia. This is the classic version. One eye is a totally different color than the other. You might have one green eye and one brown eye. This is what most people are actually looking for when they ask about this condition.
Then you have sectoral heterochromia, sometimes called partial heterochromia. This one is arguably even cooler. It’s when a single iris has a "splash" of a different color. Imagine a blue eye that has a distinct brown slice in it, almost like a piece of a pie chart. It doesn't blend; it’s a sharp, noticeable contrast.
Finally, there’s central heterochromia. This is incredibly common and often goes unnoticed. It’s when you have a different color around the border of the pupil that radiates out into the main color of the iris. You’ve probably seen people with "hazel" eyes who actually have a gold ring around their pupil and green on the outside. That’s it. That’s the "true" version of this type.
Why Does It Happen?
Genetics is the short answer.
But it's complicated. For most folks born with it—which we call congenital heterochromia—it’s just a harmless mutation. It’s often inherited in an autosomal dominant fashion, meaning if one parent has it, there’s a decent chance the kid might too. However, sometimes it just pops up out of nowhere during embryonic development.
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There are specific conditions linked to it, though. Waardenburg syndrome is one of the big ones. It can cause hearing loss and changes in hair and skin pigmentation, alongside those distinct eyes. Another one is Sturge-Weber syndrome.
But wait. What if you weren't born with it?
This is where things get serious. If your eyes start changing color as an adult, that’s acquired heterochromia. This isn't just a fun "fact about me" for a dating profile; it’s a medical red flag. It can be caused by eye injury, inflammation (like uveitis), or even certain glaucoma medications. Ever heard of Latisse? The lash-growing stuff? It can actually darken the iris over time.
Then there’s Fuchs' heterochromic iridocyclitis. It’s a mouthful. Basically, it’s a chronic inflammation that causes the pigment in one eye to wash out, making it look lighter than the other. It can lead to cataracts or glaucoma if you aren't careful.
The David Bowie Myth
We have to talk about Bowie.
People always cite him as the poster child for heterochromia. Truth is? He didn't actually have it. Not the genetic kind, anyway.
Bowie had a condition called anisocoria. When he was a teenager, he got into a scrap over a girl and took a punch to the eye. The injury paralyzed the muscles that contract the pupil. His left pupil was permanently dilated. Because a huge, dark pupil doesn't reflect light the same way a constricted one does, his left eye always looked much darker than his right blue eye. It was an optical illusion caused by trauma, not a difference in iris pigment.
Real heterochromia is found in people like Mila Kunis (who has one brown and one green eye due to chronic iris inflammation she had for years) or Kate Bosworth.
Is It Dangerous?
Usually? No.
If you’ve had two different colored eyes since you were a baby and your doctor has given you the thumbs up, you’re just part of the roughly 1% of the population with this trait. It’s a cosmetic anomaly.
However, if you notice a color shift later in life, get to an ophthalmologist. Like, yesterday. New changes in eye color can signal Horner’s syndrome or even ocular tumors like melanomas. Iris tumors can add pigment to an eye, making it look darker. It’s rare, but you don't play games with your sight.
Cultural Perks and Oddities
In the animal kingdom, we see this all the time. Siberian Huskies, Turkish Vans, and certain Australian Shepherds are famous for it. We call them "odd-eyed." In humans, it’s historically been viewed with a mix of superstition and fascination.
Some cultures viewed it as "ghost eyes"—the ability to see into both heaven and earth simultaneously. In the modern era, it’s mostly just a "wow" factor. It’s become a sought-after trait in the modeling industry because it creates a "memorable" face. It breaks symmetry in a way that’s weirdly hypnotic.
Dealing with the "Different" Look
If you have it and hate the attention, colored contact lenses are an easy fix. But honestly? Most people who have heterochromia embrace it. It’s a built-in icebreaker.
If you are a parent and you notice your newborn has mismatched eyes, don't panic, but do mention it at the next check-up. The pediatrician will likely want to rule out things like Horner’s syndrome (which involves a droopy eyelid) or those aforementioned genetic syndromes. Most of the time, they’ll just tell you your kid has a unique look.
Actionable Steps for Eye Health
Understanding what is it called when you have different colored eyes is just the start. Whether you have heterochromia or "boring" brown eyes, your iris health matters.
- Baseline Eye Exam: If you have congenital heterochromia, ensure you've had at least one comprehensive exam to rule out underlying syndromes.
- Watch for Changes: If your eye color shifts, fades, or darkens—even slightly—book an appointment with an ophthalmologist immediately.
- Check the Pupils: Look for anisocoria (uneven pupil size). If one pupil is significantly larger or smaller than the other, especially if it's a new development, seek medical advice.
- Photo Comparison: If you’re unsure if your eyes are changing, look back at high-resolution "red-eye" photos from five or ten years ago. It’s the easiest way to track pigment migration.
- Sun Protection: People with lighter eyes (or the lighter eye in a heterochromatic pair) are often more sensitive to UV light. Wear polarized sunglasses.
Heterochromia is a fascinating glitch in the human blueprint. It’s a reminder that biology doesn't always follow the rules, and sometimes, the mistakes are the most beautiful parts. Just keep an eye on those changes—literally.