In fact, there is no blue pigment in blue eyes
Blue eyes aren’t really blue at all. It sounds strange, but it is. Most people have melanin pigment in each layer of the iris. It is because of it that the eyes seem, for example, brown. But blue-eyed people simply do not have pigment in the front layers of the iris. Ophthalmologists say: the eyes at the same time seem blue because of the play of light – just like, for example, the sky. This is called the Tyndall effect.
Only a small percentage of people on the planet have truly blue eyes
The most common eye color in the world is brown. This is about 79% of all people on earth. And only 7-8% are blue-eyed. At the same time, in some countries, this phenotype is more common than in others.
The most blue—eyed people are in Estonia and Finland. Then there are Ireland and Scotland. England closes the top 5 countries with the largest percentage of blue-eyed residents.
All people with blue eyes have a common ancestor
Scientists from the University of Copenhagen found out that 6000 years ago everyone had brown eyes. But at some point there was a mutation in the OCA2 gene, which controls how much melanin we produce. This mutation «turned on» the appearance of people with blue eyes.
Some children have blue eyes that turn brown with age
It often happens that the baby’s eyes gradually change color from bright blue to green or brown. That is why it is impossible to say exactly what eye color the child will have, at least until the age of six months.
The point here is that when a child is born, melanin is not yet completely «deposited» in the iris of the child’s eye, as a result, the iris becomes blue. But after a certain period, the production of melanin either increases, changing the color of the child’s eyes, or not, leaving a heavenly shade for life.
Brown-eyed parents may have a baby with blue eyes
This is stated in an article published by the University of Delaware. And, by the way, two blue-eyed parents can give birth to a brown-eyed baby.
Eye color is determined by several different genes, as well as the interaction between them — this is how genetics works. In a way, it’s like a lottery.
Blue eyes are more sensitive to light than others
«From a clinical point of view, people with blue irises are usually more photosensitive,» ophthalmologist Ruth Williams told Everyday Health. «This is probably due to the minimal amount of light—absorbing pigment in the eye.»
People with blue eyes may have an increased risk of cancer
This is stated in a study published in Everyday Health. Blue-eyed people are more at risk of developing melanoma of the vascular membrane of the eye than brown-eyed people. «People with light irises need to wear sunglasses with UV protection,» doctors say.
Blue-eyed people see worse
According to optometrist Richard Eason, the color of your eyes can affect the quality of vision. «Due to the lack of pigment in lighter eyes – such as blue or green — much more light gets into the eyes and there is a problem with glare,» he shared in an article in ESPN.
It is easier for women with blue eyes to give birth
This information became known thanks to a study conducted by Dr. Inna Belfer, a geneticist from the University of Pittsburgh. She found that women with light eyes experience less pain and discomfort during childbirth. She also found that light-eyed women are less likely to develop anxiety or depression after having a baby than dark-eyed women, and all thanks to less melanin.
Blue-eyed men prefer girls with blue eyes
Another funny fact about blue eyes is related to men and their dating and relationship preferences. According to a study published in the journal Behavioral Ecology and Sociobiology, blue-eyed men find blue-eyed girls more attractive than women with any other eye color.
By the way, brown-eyed people turned out to be less picky. For them, the color of the partner’s eyes was unimportant.
The chances of being born with blue eyes are much lower than with brown, but blue is not the most unique of all possible. It is actually quite common, 8-10 percent of all inhabitants of the Earth can boast blue eyes.
Another 5 percent have amber eye color, but it is sometimes confused with brown. Green is much rarer than any of these shades, since only 2 percent of the world’s population is endowed with this phenotype.
The most unique eye shade in the world is gray, red or purple eyes (which in most cases occur in people with special forms of albinism) and eyes with heterochromia (eyes with different iris color), and they can be seen in less than one percent of all inhabitants of our world.
