Everything You Need to Know About Your Baby’s Eye Color

Your baby is full of surprises — and their eye color is no exception! Most often blue-gray or brown/black in the first few months, the pigments in their irises will gradually develop and settle into their final color.

When can you be sure, and how can you try to predict the true color? Here’s everything you need to know.

How is a baby’s eye color determined?

In the human body, it’s melanin that determines the color of various parts of our body. It’s a dark pigment found in the cells of the skin, eyes, hair, and body hair… Think of melanin as paint — it’s what colors the canvas! Over time, it’s melanin that determines your baby’s eye color.

More specifically, it’s the amount of melanin present and its distribution in the iris (the colored part of the eye) that determines your baby’s eye color. Its distribution across the different layers of the iris explains whether your baby will have lighter or darker eyes. The more melanin in the iris, the darker the eyes will be — and vice versa.

When is a baby’s eye color final? Can a baby’s eye color change after birth?

To get an idea of your baby’s final eye color, you’ll need to wait until just before their first birthday if they have darker eyes, and up to eighteen months if they have lighter eyes. Before that, the eye pigments are still being produced. That’s why most babies are born with lighter eyes than their final color.

At birth, you’re only seeing the deepest layer of the iris (usually dark brown or blue-gray for babies with light skin). Month after month, the upper layers of the iris will develop and reveal their final color — or almost: in some cases, hormones produced during adolescence can still affect the shade!

Want to learn more? Feel free to download the May app, where you’ll find plenty of resources to support and guide you throughout your journey as a new parent.

How is a baby’s eye color linked to that of their parents? Is it possible for a baby’s eye color to differ from their parents’?

Of course, the genetic makeup passed on by the parents plays a major role in the factors influencing a child’s eye color. There’s a very high chance that your baby will inherit the eye color of one of their biological parents. But that doesn’t mean the odds are 50/50 — far from it.

Sometimes, certain genes can skip one or even several generations. For instance, even if both parents have brown eyes, a baby can still be born with the light blue eyes of their grandmother. A person’s genetic makeup is a mix of their biological parents’ genes — but also includes combinations from earlier generations.

Can a baby’s eye color be predicted based on the parents?

As we just saw, the genes passed down by biological parents heavily influence a baby’s eye color, even though genes from earlier generations may also come into play.

Putting those cases aside, if each parent passes on their own genes, you might assume that if one parent has blue eyes and the other has brown eyes, the child has a 50/50 chance of inheriting either color. Well — not quite.

Some genes are considered “dominant,” while others are “recessive” (recessive genes are overshadowed by dominant ones). Brown eye color comes from a dominant gene, while blue eyes are associated with a recessive gene. That’s why a child is more likely to have brown eyes if one of the parents passes on the brown gene.

However, life is full of surprises — even if both parents have eyes of the same color, and that color is linked to a dominant gene (like brown), you still can’t be certain what color your baby’s eyes will be.

For example, if both parents carry one blue and one brown gene, the baby has a 1 in 4 chance of inheriting both blue genes and having blue eyes, a 2 in 4 chance of inheriting one brown and one blue gene (and thus having brown eyes but still carrying the blue gene), and a 1 in 4 chance of inheriting both brown genes.

So, it’s possible to make predictions with varying levels of reliability depending on your situation — by considering your own eye color and that of your parents — but it’s impossible to be 100% sure of your baby’s final eye color before birth, and even up to around 8 to 18 months afterward.

What is the most common eye color in newborns?

To revisit what we mentioned earlier: eye color is determined by the amount of melanin in the iris. Most often, babies with lighter skin are born with blue-gray eyes, while babies with darker skin are usually born with brown or even black eyes, as their genetic makeup tends to include a higher concentration of melanin.

Did you know?

Eye color can also result from a genetic “mutation.” For example, heterochromia (where the two eyes are different colors), or albinism (which results in very pale skin and red eyes).

If you’d like to learn more about key milestones in your baby’s development, feel free to check out our other articles:

• At what age do babies start talking? Everything about first words
• Guide to measuring baby’s shoe size month by month
• When do babies start rolling over, and how can you help?
• Motor skills: When can a baby sit up?

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Photo: nualaimages, Envato

This text was translated from French by an artificial intelligence. The information, advice, and sources it contains comply with French standards and may therefore not apply to your situation. Make sure to complement this reading by visiting the May ES/UK app and consulting the healthcare professionals who are supporting you.