Why Do Babies' Eyes Sometimes Change Color?

like fingerprints, and they generally can. Though your eyes can experience changes due to some diseases, medications, or the process of aging over the course of your life. But if you've ever hung out with a newborn through their first birthday or so, you may have noticed that their eyes completely changed color from blue to well, any other color. Don't worry. There's no cause for alarm. Changing eye color

is a normal part of baby development. Anywhere from about nine months to three years of age, a baby's eye color sets on a relatively permanent hue as more melanin is released into their eyes. When you notice someone's eye color, you're looking at a part of the eye called the iris, which is a fibrous ring that controls sides of the people and contains melanin. Melanin is a pigment that gives

color to our hair, eyes, and skin. Our bodies don't really step up melanin production to full levels until after we're born. It can take several months to several years for our skin and hair color to set to our personal baseline. This is also why some babies born blonde developed darker hair throughout childhood. Depending on the amount of melanin in the iris, it can be shades of gray, green, hazel, amber, brown,

or even pink or red. Pink or red will occur because of a condition called albinism, in which our cells develop very little or no melanie. Without melanin, our irises are clear, so the red we see is the blood vessels inside the eye. And eye color isn't just for esthetics. Like most of your biology, eye color has a purpose. Thousands of years ago, the first humans all had brown eyes. Just like the melanin in our skin cells protects against

the sun's damaging u V rays. Melanin in our eyes can keep harmful rays from causing long term damage like cataracts or rare types of eye cancer. As humans migrated and settled in climates with less harsh sun exposure, they required less melanin and human genetics adapted, though the most common eye color is still brown across the world. Interestingly, all melanin is brown. The more melanan and eye has,

the darker it will appear. In eyes that have less melanan, like the ones that appear blue or green, less light is absorbed by the iris, and that means that more light is reflected and it's atters around the eye, and a phenomenon called the Tindal effect. It's physically similar, though not identical, to why the sky appears blue from light scattering in the atmosphere, or why our veins appear blue from light scattering through our skin. Of course, heredity plays

a role in eye color. A person's hereditary eye color can be straightforward, such as when two parents with a dominant brown eye gene have a brown eyed child. However, research has identified sixteen genes that are involved in determining a person's eye color. Two parents with a recessive blue eye gene can have a child with brown eyes because of modifier genes or mutations. Gene mutations occur when genes are misspelled or turned off due to environmental conditions or disease.

The point is genetics are complicated, but it's why you are the only person in the world with your eyes, and so go ahead and take a longer look in the mirror. Today. Your eyes tell a unique, thousands year old story that started with your ancestors and now includes you. Today's episode is based on the article why do babies Eyes Change color? On how stuff works dot com, written by Alison Troutner. Brain Stuff is a production of I Heart Radio in partnership with how stuff works dot Com,

and it's produced by Tyler Klang and Ramsey Young. Four more podcasts from my heart Radio. Visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.