Physiological characteristics that affect the color of the iris of the eye
The primary pigment that determines hair color, skin tone and eye color of any person melanin. Its concentration has fundamental effect on the coloring of the iris of the human eye: the more melanin, the darker the eyes. So, brown-eyed people are seen to have the maximum concentration of pigment, and blue-eyed — minimal. Slightly eye color is determined by the concentration of most fibers of the iris. Here also there is a direct correlation: the higher the concentration, the darker the eyes.
Red eyes of albinos are characterized by a complete lack of pigment, resulting become visible blood vessels in the iris.
The amount of pigment in the cells is affected by hereditary factor. The dark color is dominant and light is recessive. The world's greatest number of people has brown eyes, and the most rare green-eyed representatives of the human race, there are only 2% of the total population of the planet.
At what age the eye color becomes permanent
According to the physiological characteristics of the structures of the human body, the pigment produced by special cells melanocytes. Their work begins immediately after the appearance of a baby into the world, and after a while. Thus, the pigment builds up gradually, from day to day. That is why some parents say that the eye color of the baby is changing almost daily. The average apparent color change of the iris starting from the age of three the child.
Often the final color of the eye crumbs can be seen already in the six-month age. However, there are cases when a change amount of pigment can last up to two and even to three years.
Sometimes in the body there is complete heterochromia is an irregular distribution of pigment. This leads to the fact that the little one's eyes are painted in different colors. Partial heterochromia affects the color of different parts of the iris. Thus small differences in the eye color is not very noticeable.
However, in case of heterochromia, it is necessary to show the child the ophthalmologist, in order to deal with undesirable consequences of the breach.
To predict what color eyes will the baby impossible. From the point of view of genetics, this trait is inherited according to Mendel's law: brown-eyed parents are born brown-eyed children and blue-eyed — blue-eyed. However, to give a precise answer to this question can only time.