How Your Genes Set Your Eye Color
Your eye color is set by your genes. In this guide I will show you how that works in plain words. You will learn why brown eyes are most common, why blue eyes can skip a family line, and how two brown eyed parents can have a blue eyed child. Let us go.
What Are Genes
Genes are the tiny bits of you that you get from your mom and dad. They set a lot of things about you, like your hair color, your height, and your eye color.
You get two copies of each gene, one from each parent. The two copies can be the same or different. How they mix sets your look.
The Main Gene For Eye Color
The main gene for eye color is named OCA2. It tells the body how much pigment to put in your iris. More pigment means brown eyes. Less pigment means blue or green eyes.
There is also a gene named HERC2 that can turn OCA2 on or off. If HERC2 is set a certain way, the body makes less pigment, so the eyes look blue.
Brown Is The Top Gene
The brown eye gene is the top one. If you get a brown gene from one parent and a blue gene from the other, you will have brown eyes. The brown gene wins.
This is why brown eyes are the most common in the world. The brown gene is hard to hide.
- Brown gene is the top one.
- Brown plus blue makes brown eyes.
- Brown plus green makes brown or hazel eyes.
- Brown is the most common eye color on earth.
How Two Brown Eyed Parents Can Have A Blue Eyed Child
This is a top question. Two brown eyed parents can have a blue eyed child if both parents carry a hidden blue gene. The brown gene is on top, so the parents have brown eyes. But they can pass the blue gene to the child.
If the child gets a blue gene from each parent, the child will have blue eyes. This is rare but it can happen.
How Two Blue Eyed Parents Have Blue Eyed Kids
Two blue eyed parents will most of the time have blue eyed kids. Since both parents only have blue genes to give, the child gets blue genes from both sides.
In very rare cases, the child can have brown eyes. This can happen if a new gene change pops up, or if the eye color is set by more than one gene.
Why Green And Hazel Are Rare
Green and hazel eyes need a mix of genes to show up. The mix is less common than the pure brown or pure blue combo. So green and hazel are rare in the world.
Green eyes also need a low amount of pigment plus some light scatter. This mix is not common, which is why only 2 in 100 people have green eyes.
Eye Color Gene Chart
Here is a chart to show how the genes mix. This is a simple view, since real life has more genes at play.
| Parent 1 | Parent 2 | Child Can Have |
|---|---|---|
| Brown | Brown | Brown, hazel, or rarely blue |
| Brown | Blue | Brown, or rarely blue |
| Brown | Green | Brown, hazel, or green |
| Blue | Blue | Blue, or rarely brown |
| Blue | Green | Blue or green |
| Green | Green | Green or blue |
| Hazel | Hazel | Hazel, brown, green, or blue |
Why Some Eyes Are Two Different Colors
Some people have one brown eye and one blue eye. This is named heterochromia. It can come from a gene change, an injury, or some illness. Most of the time it is safe and just a fun look.
Some people also have one iris with two colors, like a brown patch on a blue eye. This is also a form of heterochromia.
Can Genes Predict Your Childs Eye Color
You can make a guess, but it is not a sure thing. Look at the eye colors of you, your partner, and your parents. Then use the chart above to see what is most likely.
A DNA test can give a more true guess. But even a DNA test can not tell you 100 percent. Eye color has more than one gene at play.
- Look at the eye colors in your family.
- Use the gene chart for a guess.
- A DNA test can give a more true read.
- Even DNA can not tell you 100 percent.
- Eye color has more than one gene at play.
Fun Facts About Eye Color And Genes
Here are some fun facts I have learned about eye color and genes.
- All blue eyed people may share one old family root.
- Brown eyes are the most common on earth.
- Green eyes are most common in Ireland and Scotland.
- Some babies are born with blue eyes that turn brown later.
- Two different colored eyes is named heterochromia.
Key takeaways
- Your eye color is set by genes from both parents.
- The brown gene is on top, so brown eyes are most common.
- Two brown eyed parents can have a blue eyed child if both carry a blue gene.
- Green and hazel eyes need a rare gene mix.
- Eye color has more than one gene at play, so it can skip a generation.
FAQ
Can two blue eyed parents have a brown eyed child?
It is rare but it can happen. Eye color has more than one gene, so there is a small chance.
Where do green eyes come from?
Green eyes need a mix of low pigment and light scatter. They are most common in some parts of Europe, like Ireland and Scotland.
Are eye colors from mom or dad?
Both. You get one gene copy from each parent. The mix sets your eye color.
Can my eye color skip a generation?
Yes. A hidden blue gene can skip a generation and show up later in a child.
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