What determines the color of your eyes?

Brown, blue, green, different colored eyes…It can not be said that there is a wide range of eye colors but what we have is beautiful enough… and what determines the color of your eyes?

It feels as if the eyes can see far beyond the obvious and even if they do not have a voice, they can speak.

But if they really could, what story would they tell about their own color?

Most physical and mental characteristics we all have are determined by genetics.

We are even more prone to some diseases if they run in our families.

In this article, however, we will be focusing on eye color only.

Is it a genetic trait or it depends on something else? Let’s find out together!

Why are our eyes colored?

Prior to revealing the truth about the color of our eyes, we should know where it actually forms.

The eye color is a result of pigmentation of the iris.

The iris is responsible for the amount of light that enters your eye.

The pigment, contributing to the coloring of the eye, is called melanin.

The quantity of melanin in our irises is one of the factors, which play a role in the determination of our eye color.

This means that people with brown eyes have more melanin than people with light-colored eyes.

The genetics behind the color of the eye

Years ago, before complex technology was developed, researchers thought the color of the eye depends on one single gene.

Brown eyes are dominating over eyes with blue or green color.

This scenario totally excluded the possibility of parents with blue eyes to have a child with eyes of darker color.

However, later research has proven this theory to be quite wrong.

The eye color is in fact determined not by one, but by few genes.

The region of chromosome 15 is exclusively involved in the process.

This is due to the fact that near the chromosome 15 are located two genes very close to each other: OCA2 and HERC2.

OCA2 produces proteins that are responsible for the amount of melanin in the iris.

Another gene near HERC2 contains a part of the DNA, controlling the activity of the OCA2.

Of course, there are other genes that take part in the determination process of the eye color.

But they are not β€œso important”, so to say.

Such are ASIP, IRF4, SLC24A4, SLC24A5, SLC45A2, TPCN2, TYR, and TYRP1.

Now that you know all this, what do you think – can parents with blue eyes have a child with brown eyes?

Of course, they can! There are many possibilities for the way the genes of both parents will mix but the chances are quite low.

Nevertheless, if mama and papa have brown eyes, it is most likely that their kid will have dark-colored eyes too.

Another option – when being born, a child may have blue or even violet eyes.

This is the case of my little brother.

He was a blue-eyed baby angel.

While growing up though, his eyes changed their color to a bit darker color and now he has green/hazel eyes.

Why does this happen?

Simply because the baby did not have the pigment melanin, but it eventually developed as the child aged.

As you may also know, there are people whose irises have different colors (like some husky dogs).

This condition is called heterochromia and it can be caused by a number of reasons: disordered pigment transport, a local trauma before or after birth, inflammation, etc.

Different eye colors

Let’s talk about the color itself.

It was found that the iris can be classified in seven different colors, namely: amber, blue, brown, gray, green, hazel or red.

Here is some more information about all six:


It happens quite often that people confuse amber eyes for hazel.

The amber-colored have a golden or copper color, whereas hazel eyes tend to have blue or green flecks as well.


We already said that people who have light-colored eyes have less amount of the pigment melanin.

This is especially true for people with blue eyes.

Something else interesting about blue-eyed beauties is that they all are related!

Back in the days, a few thousand years ago, there were no people with blue eyes.

Everyone had brown eyes.

But then, all of a sudden, a mutation appeared.


Most people around the world have brown eyes – between 70 and 90 percent of the world’s population!

People with brown eyes have the largest amount of melanin in their irises.

This means that brown eyes have better protection from the sun than light-colored eyes.

However, you should still wear sunglasses!


People say that only 3 percent of the people around the world have gray eyes.

They have flecks of gold and brown and tend to change color, depending on the light, clothing, and mood.


t is probably surprising but green eyes are even rarer than gray eyes!

Only 2 percent of the population has green eyes.

The amount of melanin is from low to moderate.

Research suggests that there have been people with green eyes since the bronze age.


People with hazel eyes have most melanin after brown-eyed beauties.

Hazel eyes have gold, brown or green flecks.


Yes, red eyes are really a thing but a very rare one.

You can see the blood vessels behind the iris, which actually causes the redness.

This is due to the lack of melanin.


Just like almost every part of our bodies the color of our eyes depends on genetics.

You can not be 100 percent certain though, if your kid is going to have brown, blue or green eyes, no matter what eye color do you and your partner have.

Besides this should not worry you in any way because every person has unique eyes and every color is absolutely beautiful!

And in order to keep your eyes healthy (no matter which color they have), make sure to try our blue light-blocking software Iris – it comes with a few different modes, which enables you to choose the one suiting your needs.

By blocking the blue light emitted from your screen, Iris provides you a good night’s sleep, no fatigue, and no tired eyes.





Author: Ilina Stoyanova
Publisher: Kalina Shushlina

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