Eye Colour: How It Works by: sophie baca

Imagine living thousands of years ago. The whole world made up of just brown eyed beings. The one day, you see a person with eyes that are like the sky. If I were them, I would be baffled, possibly even scared! This was probably what it was like for a person living thousands of years ago to see the first ever blue eyed person. Now some of those people may have been wondering, how did that happen? What’s wrong with those person’s eyes? Well, even though it is nothing unusual for us to see a blue eyed person now, you might still wonder how you got your own eye colour. Read further to find out what makes up your very own, unique eye colour.

Quick Fact: The world started out with just one eye colour - brown then due to genetic mutation came the first blue eyed person which then led to green, hazel, etc.

What Eye Colours Are There In The World?

The 7 Eye Colors

There are 7 eye colors in the world ranging from the darkest browns to the lightest blues. But some eye colors are more common or rare than others. Here is a list ranging from the most to least common eye colors.

Brown - over 55%

blue - 8%

hazel - 5-8%

green - 2%

Amber, violet, and silver - rare

What are some possible ways to determine eye colour?

Chromosomes and Genes

One thing that can determine your eye colour is your parent genes. The way this works is that you inherit or get 1 chromosome from each parent when you are conceived. Scientists believe that there are 16 chromosomes that can help determine your eye colour. The two main genes are OCA2 and HERC2. Think of it like this. There are sixteen colours of paint. You mix them all up in a plate with different amounts of everything. A lot of the time it will turn out brown. But sometimes it will be blue, green or hazel. Possibly sometimes silver, violet, or amber.

Melanin and Pigment

Melanin Over pigment

There are two main factors that create your eye colour. Those factors are pigment and melanin. Pigment is the natural colouring in your iris. And melanin is the dark, brown, or black pigment in the iris of your eye. If you have brown eyes, that means you have more melanin and less pigment in your eye. If you have light eyes, then you have less melanin in your eyes and more pigment.


Determining Eye Color From Alleles Pairs

Another thing that determines your eye colour is the alleles. Alleles is a gene that you inherit from each of your parents. Let's say you inherit a brown and and green alleles. This means that you will ending up having brown eyes. You will end up having brown eyes because the brown alleles is stronger than the green one. The darker the alleles, the stronger it is. But if you inherit two hazel alleles, then you will have hazel eyes because they are the same.

People or animals with two colours of eyes is a condition called "heterochromia."

Does Your Eye Colour Stay The Same?

Eye Colour From Birth - When you are born you could have any eye colour But that may not be the real colour of your eyes. When babies are born, they are still developing the colour of their eyes. Sometimes the colour will stay the same. Other times it will change. This is not a dangerous process, it’s not unusual at all actually. The true eye colour will usually come around age three.

Changing Eye Colour In Light - Some eye colours actually appear to change colour when they are shown to light. Lighter eyes (green, hazel, blue) seem to change shades or even colour in light. This is due to the pigment in your eye’s iris compressing or spreading out when the size of the pupil changes. Your pupil size changes when exposed to light. In dimmer light your pupil enlarges. Also wonderopolis says, “depending upon the amount and diffraction of light people’s eyes may seem to change colour as well.”

All about vision says, "Her eyes may be blue only temporarily; babies' eyes can change colour if the brown pigment melanin develops as they grow."

So next time you look in the mirror and see your light blue eyes, or dark brown eyes. You’ll hopefully have an idea of why you have your very own unique eye colour. Maybe it’s because of your parent genes, or maybe it’s because of your alleles. Who knows! All we know is, is that each and every eye colour is beautiful.

Created By


Created with images by Look Into My Eyes - "It's easy to get lost in this blue eye..." • ericmay - "Amber Eyes" • gbyat - "animals dog dalmatians"

Made with Adobe Slate

Make your words and images move.

Get Slate

Report Abuse

If you feel that this video content violates the Adobe Terms of Use, you may report this content by filling out this quick form.

To report a Copyright Violation, please follow Section 17 in the Terms of Use.