Image: www.quora.com
Eye color is a distinct part of a person’s appearance. It is included on a driver’s license and other forms of identification. It is also one of the primary descriptors used in a missing person’s report.
Eye color is a trait that is controlled by multiple genes and often an intermediate heritage bowl characteristic. Eye color is determined by two distinct factors:
- The pigmentation of the eyes iris.
- The frequency-Dependence of the scattering of light by the turbid medium in the stroma of the iris.
At one time every human in existence had brown eyes. As humans begin to migrate around the globe traits in humans begin to change.
People in northern countries tend to have lighter colored eyes and skin. In comparison, darker eyes and skin color are more common in warmer southern regions. People in these regions tend to develop more melanin.
The American Academy of ophthalmology (AAO) surveyed Americans to find out how prominent certain eye colors were:
- Brown eyes – 70% to 79%
- Blue eyes- 8% to 10%
- Hazel eyes-5%
- Amber eyes-5%
- Greyeyes 3%
- Green eyes 2%
Aside from the traditional eye colors people can also have what are known as:
- Red or violet eyes which occur because of a lack of pigmentation in the eye. The lack of pigmentation exposes the blood vessels underneath and appear to be red or violet less than 1% of the world’s population has this condition also known as albinism.
- Heterochromia this refers to people with two different colored eyes it can occur at birth or due to injury, medication or illnesses. Heterochromia is also in <1% of the population.
Sources: