Heard your cutie's peepers may go from blue to brown? Find out why and when a baby's eyes change color, and how genetics influence their physical development.

Advertisement

You've already fallen in love with your baby's eyes, but as it turns out, they could change color within their first year of life. This is especially true if your little one has fair skin and light eyes. Keep reading to learn the reason behind this phenomenon and when to expect the change.

An image of a baby with their mother.
Credit: Getty Images.

Why Does Eye Color Change?

When babies are born, especially fair-skinned ones, their eyes are usually light-colored because they have very little melanin (a type of pigment that gives color to the eyes, skin, and hair). "The amount of melanin in the iris, the colored part of the eye, determines what color a person's eyes will be," says Douglas Fredrick, M.D., a pediatric ophthalmologist at Stanford Children's Health in Palo Alto, California. After birth, light stimulates the production of melanin, which is why eye color may darken or change over time.

Note that the color of the pigment does not cause the change; there is no blue, gray, green, or hazel pigment in the eye, Dr. Fredrick says. Brown is the only pigment that exists in the eye, and the amount of brown pigment determines whether a person's eyes will be light or dark, he explains.

What Eye Color Will My Baby Have?

Genetics control how much melanin (or pigment) a person will have in their body. Essentially, DNA from parents determines if a baby's eyes will be blue, brown, green, or another color. It may seem like a simple equation: One brown-eyed parent plus one brown-eyed parent should equal one brown-eyed baby, right? But that's not necessarily the case

Multiple genes in the body contribute to eye color, says Dr. Fredrick. Even if a baby's parents both have brown eyes, it's possible for the baby to end up with blue ones if the parents have the genes for blue eyes somewhere in their genetic makeup. Indeed, a baby's eye color depends not only on Mom and Dad, but grandparents too, says Jean Moorjani, M.D., a pediatrician at Arnold Palmer Hospital for Children in Orlando.

It's nearly impossible to predict your baby's eye color in advance. "Nobody, the doctor included, can predict what color the eyes will be once the baby gets older," Dr. Fredrick says. And what your baby eats or does, and how much you expose them to light, doesn't matter either. It's all up to genetics and nothing more.

That said, if your baby was born with brown eyes, it means they already have the amount of melanin assigned by their genetic code, so their eye color won't change. Also, not every baby with light-colored eyes experiences a darkening in color; sometimes the blue, green, gray, or hazel is here to stay!

When Will My Baby's Eyes Change Color?

Typically, you'll see the biggest eye color change in the first 6 to 9 months of life, Dr. Moorjani says. Over several weeks or months, you may notice your baby's eyes getting darker. The change is so gradual that you may not notice until, one day, they wake up and surprise you with a different eye color!

By 12 months, most babies will have their permanent eye color, although Dr. Fredrick says that some children's eye color may still change up until age 6 (but this occurrence is rare and the change won't happen overnight).

When to Call the Doctor

Generally, your baby's eye color will change without affecting their vision or causing any problems. But if only one eye changes color (which is very rare) or if you notice cloudiness in your baby's eye, contact the pediatrician or pediatric ophthalmologist.