How does the eye color form?

The eyeball includes several shells. Behind the upper membrane, a transparent cornea, there is a vascular membrane equipped with blood vessels and pigment cells. The front part of the eye it is represented by an iris, which is responsible for the color of the eye. Iris has special cells: chromatophores containing pigment melanin, which shines through the cornea. The amount of melanin determines the color of the eyes: a large number creates dark eyes (black, brown and light brown), and less – forms light (green or blue).

People and animals also have red eyes, the owners of which are called albinos. This is due to the fact that they have no melanin at all, so the color is determined by the blood in the blood vessels of the iris.

What does the amount of melanin have to do with it?

The amount of melanin is determined by heredity. Scientists note the genetic dominance of the features associated with a large amount of melanin. Thus, the dark-eyed gene is the strongest and overcomes the genes responsible for blue and green. If one parent’s family has dark eyes and the other has bright eyes, their children are more likely to have dark eyes.

Therefore, there are much more dark-eyed people in the world than people with bright eyes. Also, the color of the eyes is determined by the belonging to a nation and the climate in which it lives. Blue-eyed nations, as a rule, live far from the equator, the owners of brown eyes – these are usually residents of areas with a temperate climate, black eyes indicate the proximity of residence to the equator. This is how nature protects the eye from sunlight: the darker it is, the better it resists blinding light. This pattern has one justified exception: the inhabitants of the Far North have dark eyes, not blue ones. The fact is that their eyes are protected from the intolerable reflection of light from the snow.

Can the color of the eyes change over the course of a lifetime?

Yes, it is possible. The Caucasian race can change from light to dark after birth. This is due to the gradual accumulation of melanin in the iris. It is believed that the final color of the child’s eyes is formed by the age of 2-3 years. Older people’s eyes, on the contrary, sometimes turn pale. This is due to a certain loss of transparency of the mesodermal layer. In addition, the color of the eyes can also change due to some diseases.

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