Having natural purple eyes is extremely rare. In fact, only a very small percentage of the global population possesses this unique eye color. So what causes purple eyes and who is likely to have them?
What Causes Purple Eyes?
Eyes appear purple when there is a low level of melanin in the iris and a higher level of collagen fibers. Melanin is the pigment that gives eyes their color. People with purple eyes have less melanin in the front layers of the iris, allowing light to pass through and reflect off the back of the iris. This causes eyes to appear a violet or purple shade.
The amount of melanin present in the iris determines your eye color. Here’s a breakdown of how melanin levels influence eye color:
| Eye Color | Melanin Level |
|---|---|
| Brown | High melanin levels |
| Green | Moderate melanin levels |
| Blue | Low melanin levels |
| Purple | Very low melanin levels |
Along with low melanin, higher levels of collagen in the iris can contribute to purple eyes. Collagen is a structural protein found throughout the body. It provides structure and flexibility to tissues like skin and eyes.
The combination of low melanin and high collagen levels allows more light to pass through the front of the iris, exposing the purple pigment at the back and creating a violet eye color.
How Rare Are Purple Eyes?
Only about 0.2% of the world’s population is estimated to have true purple eyes. That equates to around 15 million people worldwide. Here’s a breakdown of common eye colors and their estimated frequencies in the global population:
| Eye Color | Global Frequency |
|---|---|
| Brown | 79% |
| Blue | 8-10% |
| Green | 2% |
| Gray | 1% |
| Amber | 1% |
| Hazel | 5-10% |
| Purple | 0.2% |
As you can see, true purple eyes are incredibly uncommon. Certain conditions like albinism and heterochromia (two different colored eyes) may also result in purple-tinted eyes. But naturally occurring, full purple irises are very rare.
What Ethnicities Are Most Likely to Have Purple Eyes?
Purple eyes have been found across multiple ethnic groups, but they appear to be most prevalent among those with fair complexions. People of Northern European ancestry seem especially likely to have the genetic traits that contribute to purple eyes.
Here are some of the key ethnic and regional groups where purple eyes occur most frequently:
- Northern Europeans (British, German, Irish, Scandinavian, etc.)
- Eastern Europeans (Polish, Russian, Ukrainian, etc.)
- Southern Europeans (Spanish, Italian, Greek, etc.)
- Ashkenazi Jewish populations
- Middle Eastern/North African (Lebanese, Turkish, Iranian, etc.)
- Central Asians (Afghan, Kazakh, Uzbek, etc.)
- South Asians (Indian, Pakistani, Sri Lankan, etc.)
While more research is needed, genetics appear to play a key role in purple eye color. Fair skin, light hair, and light eyes are common traits associated with purple eyes. The specific genetic mechanisms remain unclear. But current theories point to combinations of variants in multiple genes that control melanin production and collagen levels in the iris.
Can Purple Eyes Change Color With Age?
Purple eyes may change color somewhat over a person’s lifetime. However, the effect is typically subtle. Here are some ways purple eyes can shift in color with age:
- Eyes may lighten from more violet to lavender shades.
- Eyes may develop more grayish tones.
- Eyes may become less vivid and intense.
These changes occur as melanin and collagen levels in the iris fluctuate naturally. Melanin production usually decreases with age. Collagen also breaks down over time. These factors can cause purple eyes to become paler or cloudier later in life.
However, purple eyes are unlikely to darken dramatically or change to brown or green hues. While some slight alterations can happen, purple eyes tend to maintain their distinctive violet coloring well into old age.
Can You Have Purple Eyes Without Any Genetic Cause?
There are a few ways people can appear to have purple eyes without genetic traits contributing to the eye color:
- Tinted contact lenses – Colored contacts manufacture purple lenses to mimic this rare eye color.
- Medical conditions – Certain conditions like ocular albinism, Horner’s syndrome, and Fuch’s heterochromic iridocyclitis can create purple-tinted eyes.
- Injuries – Trauma from injuries may cause broken blood vessels that make the iris appear more purple.
- Lighting conditions – The right lighting and reflections can make some blue/gray eyes look more violet temporarily.
However, these effects are not the same as having true, natural purple irises. Contact lenses and lighting can enhance eye color but the results are artificial. Medical conditions may also create a purple hue, but it is not genetic. So while people can mimic purple eyes in various ways, natural cases with no underlying genetic basis are essentially non-existent.
Conclusion
In summary, purple is one of the rarest eye colors in humans. These unique violet and lavender eyes are caused by low melanin combined with high collagen levels in the iris. Purple eyes are most common in people of Northern European ancestry but can occur across many different ethnic backgrounds. The eye color results from a complex interaction of genetic factors and typically remains quite stable over a person’s lifetime, with only minor shifts in shade or intensity. So if you come across someone with vivid purple irises, you are looking at a very uncommon genetic trait!
