How Rare is Each Eye Color?
When it comes to the color of our eyes, there are multiple genes that determine the shade that we see! Genes related to the production of pigments such as melanin, eumelanin, and pheomelanin dictate the color of your eyes, skin and hair. When these genes produce less pigment, the result is lighter-colored eyes. When these genes produce more pigment, darker eyes will result! Your eye color reflects a unique blend and concentration of pigments in your iris. Like fingerprints, your own eye color is something unique to you!
Brown eyes are found in 45% of the US population, but ~80% of the world’s population. It is believed that ~10,000 years ago, all humans had brown eyes and that the elevated levels of melanin protected people from the sun’s damaging rays. As people began moving from hotter climates of Africa and Asia to cooler environments of Europe, there was less need for this protection. A gene mutation occurred as humans migrated north, reducing melanin production, which led to different eye colors!
Blue eyes are seen in about 8-10% of the world’s population. Scientists believe that almost all blue-eyed people trace back to a common ancestor, who had the first genetic mutation resulting in reduced melanin production.
Hazel eyes can be found in ~5% of the world’s population. They are often a combination of green and brown and can also contain flecks of gold or orange coloring. Hazel eyes appear to shift color in different lighting.
Green eyes can be found in ~9% of Americans, but only 2% of the world’s population.
Different Colored eyes is a condition called heterochromia, where a person’s iris color doesn’t match. Heterochromia is quite rare in humans, occurring in less than 1% of the world’s population! When a person is born with it or it develops soon after birth, it is called congenital heterochromia. It is often caused by genetics, though if it develops as an adult, can be a sign of a medical condition such as glaucoma or eye tumors.
A person’s eye color can be very telling of underlying health issues that a person could be experiencing. For instance, people with lighter iris colors have higher chances of age-related macular degeneration than people with darker iris colors. When a person is undergoing liver inflammation or liver damage, it cannot remove bilirubin, leading to an accumulation in the blood which makes the sclera, or white of the eye, and skin appear yellow. Brown freckles can develop in your iris over time, often due to sun exposure. Most of these freckles are harmless but can sometimes be cancerous, so give us a call if they occur. Your eye color is completely unique to you! Remember that no matter the color, your eyes are important to take care of and protect! We cannot wait to see you for your yearly exam to ensure your eyes stay happy and healthy!
