It is said that “eyes are the window to the soul”. In reality, in some parts of the world, people don’t allow themselves to be photographed, fearing that their souls would be taken away by having their picture snapped. That might sound like a bit of a crazy idea, but have you ever wondered about another interesting aspect of our eyes? Perhaps the most notable aspect of them, in fact. How did you get your eye color?
Well, much of that depends on your parents, as the color of your eyes depend on the genes you received from your mother and father. However, it is not that simple, as a child can also have a completely different eye color than both of its parents.
What Determines Eye Color?
Each person is born with 46 distinct chromosomes that are divided into 23 pairs. Each parent provides one chromosome to make a pair. Chromosomes are comprised of DNA called genes. Genes contain a segment called “alleles”, which determine the color of your eyes. Scientist believe that about 16 different genes play a role in determining eye color, which is the reason why there are so many different eye colors out there in the world.
There are two different types of alleles: dominant and recessive. If two alleles, coming from each parent, are the same, then they are called homozygous. This will result in the child having the same characteristics of eyes as those of the parents. If two alleles are of different types, then they are called heterozygous. In this case, the dominant alleles will determine the color of the eye, while the recessive alleles will remain unexpressed.
Brown alleles are dominant over both green and blue, whereas green alleles are dominant over blue alleles. This is the reason why the most common eye color is brown. A person having both recessive and dominant alleles will have the dominant eye color, but that person is still able to retain the recessive alleles genes, which can be passed on to future generations. This is the reason why brown-eyed parents occasionally end up with a blue-eyed child.
Genes also determine your eye color by determining how much melanin is produced in your iris. Melanin is a pigment that is found in your skin and eyes. It is this melanin that determines which alleles are dominant in your eyes.
The iris of your eye contains two different layers: the back layer and front layer. The back of the iris is usually blue, but the melanin produced in the front layer determines your eye color. The greater the amount of melanin produced, the darker the eye color. Brown eyes have the most melanin, whereas green eyes have less and blue eyes have no melanin in the front layer of the iris at all. Melanin production does not begin at birth, which is the reason why most babies’ eyes appear blue.
More about Eye Color
All people with blue eyes came from the same ancestors!
Albino eyes have no melanin in either the front or back layer, so their eyes appear red or pink because of their blood vessels.
Some people also have two different eye colors; this phenomenon is called heterochromia, which is due to either an excess or lack of pigment within an iris or part of an iris.