Human eyes are one of the most interesting and complex parts of our body. Our eyes not only help us see everything around us, but they are one of the unique features that best define us. However, eye colors are determined after a series of surprising biological events take place and hold a lot of interesting information, including:
Eye colors, which are the subject of research by many scientists, are one of the first features that catch our eye in the person in front of us. Eye colors, which can even be a precursor to eye problems that may arise in the future, have interesting facts that we think you may not have heard of, if not all. Let’s move on to our list of facts about eye colors.
Interesting facts about eye colors:
- All blue-eyed people descend from the same ancestor
- You can have two different eye colors
- All humans have brown eyes.
- Each eye has a unique structure
- Blue eyes are more sensitive to light
- Eye color changes with age
- It is very difficult to predict the eye color of the baby to be born.
All blue-eyed people have a common ancestor
If you have blue eyes, you have a mutation that causes a lack of pigment in the iris. Researchers at the University of Copenhagen believe that the mutation that causes blue eyes first appeared in a human living in Europe between 6,000 and 10,000 years ago. That is, all blue-eyed people living today share a common ancestor.
You can have two different eye colors
Heterochromia is when a person has two different eye colors. This is a mutation that can often occur in cats and dogs. There are three different types of heterochromia. Complete heterochromia is when one eye is completely different from the other eye color. Partial heterochromia is when only one part of one eye has a different color from the rest of the same eye. This can occur in both eyes. Central heterochromia is the color that forms the pupil border has a different color compared to the rest of the eye.
All people’s eyes are actually brown
Our eyes can have various colors such as blue, green and hazel, but these pigments are never found in the human eye. It all depends on the amount of melanin in the iris (the ring around the pupil). Melanin, which is naturally dark brown, is also the same pigment that determines our skin and hair color. In other words, the more melanin in the iris area, the darker the eye color. Also, eye color depends on how light is scattered as it passes through the eye. The melanin we mentioned above causes a darker color to appear as it absorbs light and prevents it from reflecting off the surface of the eye.
Hans Eiberg, from the Department of Cellular and Molecular Medicine at the University of Copenhagen, explained that before the genetic mutation that caused the blue eye color 6,000 to 10,000 years ago, everyone had brown eyes. This genetic mutation affecting the OCA2 gene in our chromosomes prevented the production of brown eye color, resulting in the emergence of a new eye color. In cases where the OCA2 gene is completely affected, albinism occurs.
Each eye has a unique structure
Just like a fingerprint, the colors and patterns found in the colored part of the iris or eye are unique. In fact, this uniqueness is so great that iris scans are more successful than fingerprint recognition technology. Even identical twins do not have the same irises.
Blue eyes are more sensitive to light
Melanin protects the eye from the sun by blocking UV light. Because people with blue eyes have less melanin, they tend to be more sensitive to light and more susceptible to damage from UV rays.
Eye color may change with age
Specifically, about 15% of the white population experience a gradual change in eye color as they age. This difference in color tone may be a precursor to some diseases such as Horner’s syndrome and pigmentary glaucoma. Horner’s syndrome is a condition in which the nerves responsible for pupil and eyelid movements are damaged. Pigmentary glaucoma usually causes the iris to have a darker color.
It is very difficult to predict the eye color of the baby to be born.
Although it has to do with dominant and recessive genes, you can’t predict a baby’s eye color based solely on the eye color of its parents. According to recent scientific studies, it has been revealed that 16 different genes play a role in determining eye color. Therefore, there are many different eye colors in the world. However, because babies are born without melanin, their eye color becomes blue.
What eye color has the most in the world?
The most common eye color in the world is brown. It is estimated that around 55% to 70% of the world’s population has brown eye color. Although eye color is partially genetic, brown eye color is thought to be the dominant gene. There are also light, normal and dark brown tones of this eye color and they are quite common.
What is the rarest eye color in the world?
Although studies on the subject continue, one of the least common eye colors in the world is green. Green eyes have less melanin than brown eyes and more than blue eyes. The green eye color, which is formed by the combination of a light brown pigment known as lipochrome and a yellowish pigmentation, can appear in different tones depending on the weather and light.
So what are the rarest eye colors?
- Green – 2%
- Gray – 3%
- Hazel – 10%
- Blue – 8-10%
- Brown – 55-79%
Rare eye colors are caused by various mutations. Research reveals that thousands of years ago, everyone on earth had brown eyes. As we mentioned above, the first person to have blue eyes is believed to have a genetic mutation that reduces melanin production.
Between 55% and 79% of people have brown eyes, and dark brown eye color is most common in Africa, East Asia and South East Asia. Light brown eyes are most common in Western Asia, America, and Europe. Green eye color is found in only 2% of people worldwide.
We mentioned the blue eye color above, but the interesting facts about it are not just these: