The rarest eye colour is green.
While eye colour rarity can vary slightly depending on geographic location and ethnicity, green eyes are generally considered the least common globally.
Frequency of Eye Colours
Here's a general overview of eye colour frequency:
- Brown: The most common eye colour worldwide.
- Blue: More common than green, especially in European populations.
- Hazel: A mix of brown, green, and gold.
- Amber: A solid, golden-yellow hue.
- Green: The least common.
Why Green Eyes are Rare
Green eye colour results from a specific combination of:
- Low levels of melanin: Melanin is the pigment responsible for brown eye colour.
- The presence of the Tyndall effect: This is the same phenomenon that makes the sky appear blue. In the iris, the scattering of light by collagen fibers creates a blue hue. Combined with the small amount of yellow pigment (lipochrome) often present, the result is green.
The genetics of eye colour are complex, involving multiple genes. For a child to have green eyes, they generally need to inherit the right combination of genes from both parents, making it less likely compared to brown or blue eyes. Even if both parents have green eyes, there's no guarantee their child will inherit the trait.
In summary, the relatively low levels of melanin and the specific genetic inheritance required contribute to the rarity of green eyes.
