Eye color is a fascinating trait in humans. The colors range from the common brown and blue to the less frequently seen green, grey, amber and hazel. But perhaps the rarest eye color of all is black. So how uncommon are true black eyes, and what causes this pigmentation?
What determines eye color?
The iris is the colored part of the eye surrounding the pupil. The pigmentation of the iris comes from melanin, the same pigment that gives skin and hair its color. Two types of melanin determine eye color:
- Eumelanin produces brown/black pigment.
- Pheomelanin produces yellow/red pigment.
The amount and distribution of these melanins in the iris determines eye color. Brown eyes contain a lot of eumelanin. Green and hazel eyes contain moderate amounts of both eumelanin and pheomelanin. Blue eyes contain hardly any melanin while grey eyes have just a small amount of melanin in the front of the iris.
What causes black eyes?
True black eyes are very rare. However, they can occur for a few different reasons:
- Increased melanin: The iris contains a very high amount of eumelanin that absorbs almost all light, resulting in a black appearance.
- Medications/Disease: Certain medications like prostaglandin analog eye drops for glaucoma can increase melanin production. Pigment disorders or melanoma could also darken the iris.
- Trauma: Bleeding in the eye from a blunt force injury causes the blood to be trapped in the eye, temporarily or permanently discoloring the iris black/brown.
In most cases, a truly black iris is so dark brown it only appears black. Theillusion comes from having increased melanin levels compared to lighter color eyes. But some people do develop true black pigmentation from birth, disease, or injury.
How rare are black eyes?
It’s difficult to determine exactly how rare black eyes are since eye color statistics are limited. But most surveys suggest brown eyes are by far the most common, followed by blue.
Here is a breakdown of some research on eye color rarity:
| Eye Color | Global Rarity |
|---|---|
| Brown | 70-90% |
| Blue | 8-10% |
| Hazel | 5% |
| Amber | 2% |
| Green | 2% |
| Grey | 1% |
| Black |
As you can see, brown eyes make up the majority of eye colors globally. After blue eyes, the remaining colors occur in the single digit percentages. True black eyes are exceptionally rare at less than 1% of the population.
Eye color distribution by region
The most common eye colors also vary by geographic region and ancestry. Here are some examples:
- Brown eyes dominate in Asia, Africa and the Middle East at 75-90% prevalence.
- Lighter eyes are more common in Europe, especially in Northern/Eastern regions. Blue eyes can be up to 80% prevalent.
- The United States has a more mixed distribution, but brown eyes remain the most common.
- Some research suggests black eyes may be slightly more common in Asia, Africa and Southern Europe due to higher melanin levels.
Keep in mind there are always exceptions. While blue and green eyes are rare in Asia, for example, they can still occur due to genetic variants and intermixing populations.
What’s the rarest eye color in the world?
Based on global statistics, true black eyes are likely the rarest eye color in the world. However, some other very uncommon eye shades include:
- Violet/Purple: Extremely rare, these eyes have a hint of red/pink and get their hue from a higher amount of pheomelanin pigment.
- Red: The only known cases come from eye trauma/disease and albinism. There is no natural red iris pigment.
- Grey: Ranges in shade from light silver to almost black. Very little melanin in the iris.
- Amber: Golden honey-brown shade. Difficult to distinguish from light brown eyes.
So in summary, while brown eyes are definitely the most common worldwide, pure black eyes are likely the rarest at less than 1% of people.
Famous people with black eyes
Since black eyes are so uncommon, only a handful of celebrities are known to have nearly-black eye pigmentation. Some examples include:
- Angelina Jolie – Very dark brown that can look black
- Johnny Depp – Almost black
- Wentworth Miller – Dark brown
- Tyra Banks – Extremely dark brown
However, when photographed, lighting conditions can make brown eyes appear blacker than they actually are. True black eyes are difficult to distinguish and rarely seen even among celebrities.
Can you have black eyes from contacts?
colored contact lenses have become popular for temporarily changing your eye appearance. Brands like Freshlook offer colored contacts designed to make your eyes look black.
When worn properly, these black contacts will completely obscure your natural eye color beneath. However, there can be safety concerns with over-wearing costume contacts for long periods.
Additionally, the artificial black color tends to look slightly unnatural up close. So for realistic and safe black eyes, increased melanin pigmentation is preferable to contacts.
Conclusion
In conclusion, eyes that are truly black in coloration are exceptionally rare worldwide. Increased melanin levels can produce blackish looking eyes in some groups, but pure black irises likely occur in less than 1% of people.
Brown remains by far the most common eye shade globally, though prevalence varies by region. If you have naturally black eyes, consider yourself to have one of the rarest eye colors!