Eye color of a child

Eye Color Genetics

According to many studies, there are three main eye colors:

  • brown (dark brown)
  • green
  • blue

In recent years this approach has been criticized as too simplistic, and more and more colors are used. Most people in the world have brown eyes, the next most common are blue and gray colors, green eyes are the rarest.

Eye color primarily depends on the amount of pigment called melanin which is contained in the iris. The darker the eyes, the more melanin the iris contains, and vice versa. A small amount or absence of melanin will result in blue eyes. The total amount of melanin in the body determines the color of hair, eyes, and skin.

Eye color of a child

The color of the child’s eyes can completely differ from the color of the eyes of the parents. Although if both parents have brown eyes, then the child’s eyes will most likely also be brown. It was previously believed that eye color is determined by a single gene. A simple inheritance scheme was used, in which brown eyes prevailed over blue ones. According to this model, it was believed that parents with blue eyes cannot have children with brown eyes. More recent studies have shown that this model was too simplistic. Inheritance of eye color is a more complex process because several genes affect the color of the eyes. Although the color of the eyes of a child can often be predicted by the color of the eyes of the parents and other relatives, sometimes genetic differences lead to unexpected results.

According to a number of studies, two genes play the main role in determining eye color: HERC2 and OCA2. However, eye color is influenced by at least ten other genes. Complex interactions between genes affect eye color, which allows two blue-eyed parents to have brown-eyed children.

The genetic calculator is based on a simple model that takes into account 2 genes, with which you can explain the inheritance of eye color (brown, blue and green). In fact, eye color genetics is much more complicated. This means that this eye color calculator works for many people, but not for everyone. For more precise results, in addition to parents, the genetic calculator tracks grandparents on each side. In this model, brown dominates over green and blue, green dominates over blue, and finally, blue is recessive, that is, it is suppressed by dominant genes.