One of the most often asked questions parents have concerning the appearance of their baby is ‘What color will my baby’s eyes be?

The answer is far from simple as it generally lies in a complicated recipe of genes and hereditary factors which geneticists even today still don’t fully understand. The question of eye color, and how it is passed from parents to progeny, has been a topic of debate among geneticists for decades.

Eye color always being a fascinating topic that mystified researchers for centuries until science provided us with a better understanding of eye color and how it is inherited. When it comes to predicting a baby’s eye color, one can almost be sure the baby will be born with blue eyes.

Newborns often have blue eyes, which generally darken with increased exposure to sunlight. By the age of three, a child’s eyes will usually settle into their permanent, adult color – be it blue, green, hazel, amber, grey, dark brown or even blood red.

Eye color is inherited very similarly to the way we inherit hair color: genes for darker colors are dominant – meaning that the traits (or phenotypes) they code for take precedence over the traits coded for by genes for a lighter color. The color of a person’s eyes depends on the amount of a pigment called melanin present in the iris of the eye (melanin is also responsible for the coloring of our skin).

At each end of the spectrum you have blue-eyed people, who have relatively small amounts of melanin, while brown-eyed people at the other end have lots of melanin present. People with other eye colors generally fall somewhere in the middle of these two extremes. What determines how much melanin is present in the iris is determined by hereditary genetics.

Eye color is determined by three governing factors:
1. The parents eye colors are
2. Whether the parents are homozygous or heterozygous for that color
3. If the parents genes for eye colors are dominant or recessive

Below is a simple baby eye color prediction chart, based on heterozygous (the most likely) odds.:

and here is the sample of eye-colour calculation :

In general, inheritance of eye color is considered “polygenic”. That means that parent’s genes usually (but not always) determine the baby’s eye color. Parents can carry both of the same gene (homozygous), or, what is more likely, they carry a more dominant gene, and another less dominant gene (heterozygous).

It’s usually impossible to determine whether a parent is heterozygous or homozygous. Brown and maybe green are considered dominant. But even two brown eyed individuals can make a blue-eyed baby, because this does not always completely follow the rules (it’s therefore called “polygenic”).

Of course, genetics is a lot more complicated than the simplified examples above, and current thinking is that there are a number of genes (not just two or even three) that influence the final eye color of an individual.

Because all the permutations and interactions of the various genes concerned are beyond the scope of this article we’ve gathered a number of links to some further resources, as well as a couple of online eye-color calculators that you can try out.