A newborn’s eyes may change colour 6 months after birth

There’s little need to worry if your newborn’s eyes change colour in the year after birth. Shutterstock

The eye colour your child is born with may not necessarily be the eye colour they have for life. Read on to learn more about when, how, and why your newborn’s eye colour may change.

Eye colour at birth

Human eye colour is determined by a pigment called melanin, which is secreted by cells called melanocytes. The more melanin you have, the darker your eyes, hair, and skin are.

Melanocytes respond to light, and since newborns have spent the past several months in the womb, they haven’t been exposed to much light to trigger melanin production, says Dr. Anne Negrin, an ophthalmologist in Purchase, New York.

As babies grow, the melanin in their eyes develops, and by six to eight months of age, the colour of their eyes could be completely different than what they had at birth. The production of melanin tends to slow down around six months of age, but your baby’s eye colour can continue to change for up to a year.

What factors determine eye colour

The amount of melanin that may develop in your baby’s eyes depends on genetics, Negrin says. A small amount of melanin results in blue eyes, while a medium amount means green or hazel eyes, and those with a lot of melanin are likely to have brown eyes.

Typically, Caucasian babies are born with grey-blue eyes that may or may not change to a darker, browner colour depending on how much melanin develops. Whereas black or Hispanic babies have more melanin to start with and, therefore, are more likely to be born with brown eyes that won’t change colour.

The most common eye colour change

Brown is the most common eye colour worldwide. An estimated 79% of the world’s population has brown eyes. The second most common eye colour is blue, which makes up about 8% to 10% of the population. Finally, there’s 5% of the population who have amber or hazel eyes, and 2% per cent with green eyes.

Because brown eyes are so prevalent, the most common eye colour change in newborns is blue to brown, Negrin says. Though it’s important to note that not all newborns’ eyes change colour. And while many people assume all babies are born with light blue eyes, the majority of newborns worldwide actually have brown eyes at birth.

When you should be concerned about your baby’s eye colour

If by six or seven months of age, one eye is a completely different colour than the other eye, you should check in with a doctor as this can be a sign of a rare disease called Waardenburg syndrome, which is also associated with hearing loss.

Or if you notice your baby’s eye colour is actually becoming lighter over time, it could be a sign of ocular albinism (not to be confused with general albinism, which can produce pink or reddish eyes). Ocular albinism is a rare condition where, instead of producing more eye pigment over time, babies produce less pigment, resulting in very light-coloured eyes. Since pigmentation in the eye is crucial for the development of vision, ocular albinism is associated with significant vision problems.

Related stories about newborn care: