Eyes come in a variety of colors, from common shades like brown and blue to more unusual colors like green, gray, and hazel. But when it comes to the rarest eye color in humans, the answer may surprise you.
The Most Common Eye Colors
Before looking at rare eye colors, it’s useful to understand which eye colors are most prevalent. Here are some quick facts on the most common eye shades:
- Brown eyes – This is the most common eye color worldwide, with over 55% of people having brown eyes.
- Blue eyes – After brown eyes, blue is the next most common eye color. About 8-10% of the global population has blue eyes.
- Hazel eyes – Hazel eyes have a mix of brown and green, with some flecks of gold. About 5% of people worldwide have hazel eyes.
- Grey eyes – These eyes have a dominated by shades of grey. They are similar to blue eyes but have less melanin. Around 2% of the population has grey eyes.
So while eye colors like brown and blue are very widespread, other eye shades are much rarer. Next we’ll look at some of the rarest eye colors that exist.
Rarest Eye Colors
Here are some of the eye colors that occur less frequently in the human population:
Green Eyes
Green eyes are very rare, occurring in less than 2% of the world’s population. They are most common in Northern and Central Europe. The shade of green can vary from a dark olive green to a pale, brilliant green. The coloring comes from the combination of a low melanin amount with a yellowish lipochrome pigment.
Amber Eyes
Amber eyes are extremely rare. They are similar to hazel eyes but contain a higher amount of yellow and gold tones. This gives the eyes a golden or honey brown appearance. Amber eyes are found in less than 1% of the population.
Red/Violet Eyes
Eyes in a true red/violet shade are perhaps the rarest eye color that exists. They only occur in cases of severe albinism, when there is a complete lack of pigment in the iris. The blood vessels in the eyes give off a red/pink glow. However, these eye colors are so rare that accurate statistics are unavailable.
Heterochromia
While heterochromia refers to eyes being different colors rather than a single shade, it is still extremely rare. In complete heterochromia, one iris is a different color than the other. This occurs in less than 1% of people. Segmental heterochromia, where part of the iris is a different color, is a bit more common at 1-2% of the population.
Determining Eye Color Rarity
So which of these unusual eye shades is the rarest? While there are no precise statistics available, scientists agree that true red/violet albinism eyes are perhaps the rarest eye color in the world. Next would likely be complete heterochromia, followed by amber eyes and green eyes. Here is a table summarizing the rarest eye colors and their estimated frequency:
| Eye Color | Estimated Frequency |
|---|---|
| Red/violet albinism | Extremely rare, no precise statistics available |
| Complete heterochromia | Less than 1% of people |
| Amber eyes | Less than 1% of people |
| Green eyes | Approx. 2% of people |
What Causes Rare Eye Colors?
So what leads to these unusual eye shades? Here are some key causes:
- Melanin levels – Melanin is the pigment that gives color to the eyes. The amount and type of melanin determines eye color.
- Lipochrome pigment – This yellow/gold pigment combined with low melanin levels produces green and amber eyes.
- Albinism – A lack of melanin causes the red/violet eye color in cases of albinism.
- Genetic mutations – Mutations in genes like OCA2 are responsible for rare eye colors.
- Heterochromia – Partial heterochromia is caused by a genetic change or injury. Complete heterochromia occurs from uneven melanin distribution.
Ethnic and Geographic Origins
Rare eye colors also tend to have certain ethnic and geographic associations:
- Green eyes are most common in Northern and Central European ethnic groups.
- Amber eyes are most frequently seen in Asia, especially among East Asians.
- Albinism occurs worldwide but is especially common in groups with higher degrees of isolation.
- Heterochromia has no strong ethnic linkage.
This shows that while rare eye colors can manifest anywhere, they do have higher incidences in certain population groups.
Conclusion
When it comes to rare human eye colors, reds and violets associated with albinism are perhaps the rarest eye shades that exist. Other unusual eye colors like amber, green, and complete heterochromia are also very uncommon, each occurring in less than 2% of the global population. The unusual pigmentation for these eye colors comes from factors like low melanin levels, genetic mutations, and the presence of lipochrome pigments. So while most people have common eye colors like brown, blue, and hazel, a lucky few have the chance to flaunt these rare and striking eye shades.