Having grey eyes is uncommon, but not extremely rare. About 1-2% of the global population has grey eyes, making them one of the rarest eye colors. However, in certain parts of the world, grey eyes are more common due to genetic factors.
What Causes Grey Eyes?
Eye color is determined by the amount of melanin (pigment) in the iris of the eye. People with grey eyes have low to moderate amounts of melanin in their irises. This causes the eye to appear blue/grey rather than brown or green which require higher melanin levels.
The main genetic factor influencing grey eyes is thought to be the HERC2 gene. Certain variations of this gene reduce melanin production, leading to lighter eye colors like blue and grey. However, multiple genes likely contribute to eye color.
Where Are Grey Eyes Most Common?
Grey eyes are most prevalent in northern and eastern Europeans. This includes countries such as:
- Finland
- Estonia
- Denmark
- Russia
- Ireland
- Scotland
In these areas, up to 10-30% of the population may have grey eyes. This compares to only 1-2% globally. The high prevalence is believed to be related to natural selection favoring lighter eye colors in Northern climates.
Outside of Europe, grey eyes are rare. They are almost non-existent among Africans, Asians, Native Americans, and Aboriginal Australians due to genetic differences.
Are Grey Eyes Linked to Other Traits?
Some preliminary research suggests grey eyes may be linked to other genetic traits, such as:
- Hair color – People with grey eyes are more likely to have dark blonde, light brown or red hair.
- Left-handedness – Grey-eyed people have a slightly elevated chance of being left-handed.
- Vision problems – There may be a slight association between grey eyes and nearsightedness.
However, more research is needed to confirm if grey eyes have meaningful connections to other traits. Many proposed links are likely just coincidences.
Can Grey Eyes Change Color?
It’s a myth that grey eyes change color depending on mood or clothing. However, grey eyes may appear to “change color” in certain lighting.
This is because grey eyes have low melanin levels, making them translucent. The actual color of the eye doesn’t change, but reflected light makes them appear different shades:
- Grey/blue in natural lighting
- Greenish in fluorescent lighting
- Light brown in yellow/warm lighting
The inner, exposed iris reveals more vibrant colors, while the outer area remains greyish. But the overall genetics remain the same.
Can Contact Lenses Change Grey Eyes?
Colored contact lenses provide a temporary way to change the appearance of grey eyes. Here are some options:
- Blue – Makes grey eyes appear very light. Best for lightening the eyes.
- Green – Produces a bright, emerald effect on grey eyes.
- Brown – Gives grey eyes a darker, warmer tone.
- Hazel – Creates a multi-colored look by blending brown/green.
Contact wearers should choose an enhancing color, not one that looks artificial. Ask your optometrist for advice on choosing the best shade.
What is Central Heterochromia?
Some people with grey eyes have a condition called central heterochromia, which causes their eyes to appear multicolored. This results in an inner ring of grey/blue surrounded by an outer ring of brown/green.
Central heterochromia is harmless and caused by uneven distribution of melanin. About 10% of people with grey eyes have this trait, which can look quite striking.
Conclusion
In summary, grey eyes are uncommon globally but more prevalent in northern European populations. They likely involve genes that reduce melanin production in the iris. While intriguing, grey eyes do not indicate any special talents or defects in a person.
The rarity of grey eyes depends greatly on ethnic background and region. But ultimately there is significant diversity in eye color, with no one shade being intrinsically better.
| Region | Grey Eyes Prevalence |
|---|---|
| Finland | 30% |
| Northern Russia | 10-20% |
| Ireland | 10-15% |
| Global | 1-2% |
| East Asia | Less than 0.1% |