Each person has their own unique eyes. There are many of their colors and shades: blue, brown, black, blue, gray, green. Their color changes throughout life. By the color of the eyes, they often try to judge a person's character or some other qualities, nevertheless, the color of the eyes can definitely indicate only genetic inheritance.
What does eye color depend on?
The eyeball is the main component of the eye. It consists of several shells. The upper shell of the eyeball is the transparent cornea, then the choroid and iris. It is in the choroid that pigment cells and blood vessels are located. The iris, which is located in front of the eye, is responsible for its color. In one of the deep layers of the iris there are chromatophores, which contain the coloring pigment melanin, which shines through the cornea.
The less melanin, the lighter the eye and vice versa. Eye color is often associated with a person's place of residence. Nations with blue eyes live far from the equator, with brown ones they live in temperate climatic zones, people with black eyes live very close to the equator, in hot countries. The inhabitants of the Far North, although they live on a cold continent, have brown eyes, so their eyes are protected from the blinding reflection of snow. The lighter the eye, the worse it is protected from sunlight.
Genetic studies have proven that the gene for brown eyes is the strongest and overcomes green and blue eyes.
How did blue-eyed people come about?
Scientists at the University of Copenhagen conducted genetic studies of blue-eyed people. To conduct the experiment, Professor Eisberg invited more than 700 blue-eyed respondents of completely different nationalities. During the experiment, it was found that 99.5% of the experimental subjects had the same mutation in the gene that is responsible for the color of the iris.
Eisberg believes that all modern people with blue eyes have one ancestor. He managed to find out that the first blue-eyed man appeared about 6-10 thousand years ago during the resettlement of the inhabitants of the Middle East to Europe.
According to scientists, the mutated HERC2 gene appeared in the northwestern part of the Black Sea region.
From time immemorial, the blue color of the eyes was considered something mysterious and bewitching. There are not so many owners of eyes of this color - this can be explained by the fact that the gene responsible for the blue color is recessive, and for the brown color is dominant, so it turns out that a child can be born blue-eyed 3 times less often than brown-eyed. Scientists continue to research in this area, but now we can say that blue-eyed people are much more vulnerable to sunlight than people with dark eyes.