Eye color is one of the first things people notice about one another. The majority of the world’s population has brown eyes, about 70-80%. Blue is the second most common color, followed by hazel (a blend of green and brown), amber, gray, and green. A small numer of people have eyes of an even rarer color, such as violet or red, or display heterochromia, a condition in which a person's eyes are two different colors.
The iris is the colored part of the eye. This part surrounds the pupil -- the small black hole in the eye's middle that regulates the light. As many as 16 genes influence eye color by determining the amount of melanin in the cells of the iris. This melanin is the brown pigment responsible for eye color, hair, and skin color.
Non-brown eyes have no different color pigments. Instead, they have less melanin, absorb less light, scatter more light and reflect it along the spectrum of light color.
An iris with little melanin appears blue, while those with more little melanin appear green or hazel.
Eye color may not remain constant throughout your life. Many babies born with blue eyes experience a change in color as more pigment develops within the first three years.
Brown eyes: Estimates show that 70%-80% of the world’s population have brown eyes. In fact, the American Academy of Ophthalmology (AAO) claims that everyone on the planet had brown eyes around 10,000 years ago. About half of people living in the U.S. and a higher population in Africa, and Asia are brown-eyed.
Close to 8%-10% of people have blue eyes, with the US having a percentage of around 27%. Scientists believe that all blue-eyed people can be traced back to a common ancestor, who probably had a genetic mutation that reduced their melanin in the iris.
Amber eyes have a little more melanin than hazel eyes, and still account for approximately 5% of the population. More people living in Asian, South American, Spanish, and South Africa are more likely to be amber-eyed
Close to 3% of people in the world have gray eyes. The gray-eyed have little or no melanin in their iris but have more collagen in the stroma part of the eye. The collagen is scatted by light to make the eyes look gray.
Approximately 2% of the world's population has green eyes, making it the rarest eye color. Nevertheless, green eyes are common in a few parts of the world, like Ireland and Scotland. These people make up about 9% of the U.S. population.
Persons with albinism have very little or no melanin in the iris. The lack of pigment leads to red or violet eyes and often problems with their eyesight. A person may also have more than one eye color, a condition called Heretochromia, which affects less than 1% of people.
The AAO states that those with central heterochromia have iris with two differently colored rings, while those with complete heterochromia have one iris with a different color.
Brown Eyes %
Blue Eyes %
Intermediate Eyes %
Blue eyes are rare globally, but 89% of people in Finland and Estonia have them. Among those with green eyes, 75% come from Scotland or Ireland.