Hey everyone! Welcome back to our channel. Have you ever wondered what decides your baby’s eye color? In this blog, we’ll cover what determines your baby’s eye color, whether you can predict it, and what your baby’s eye color might tell about their health. Stick around to discover the science behind those beautiful baby blues, greens, browns, and everything in between!

Eye color is determined by the genes we inherit from our parents. It’s all about the combination of genetic material that gets passed down. Let’s break it down!
Eye color is one of the most complex genetic traits? For a long time, scientists thought it was all controlled by a single gene. But now we know it involves more than 50 different genes! That’s right, 50 genes working together to decide if your baby will have blue, brown, green, or even gray eyes.
The main players in this genetic orchestra are two genes called OCA2 and HERC2, located on chromosome 15. But they don’t work alone. Other genes like ASIP, IRF4, and TYR also jump into the mix, influencing eye, skin, and hair color.
So, how does this work in the eye itself? The colored part of the eye is called the iris. Eye color results from the combination of pigments produced in a layer of the iris known as the stroma. There are three main pigments involved:
  1. Melanin: A yellow-brown pigment that also affects skin tone.
  2. Pheomelanin: A red-orange pigment responsible for red hair, commonly found in people with green and hazel eyes.
  3. Eumelanin: A black-brown pigment prevalent in dark eyes, influencing the intensity of the eye color.

The specific combination of these pigments, along with their distribution and absorption by the stroma, determines the appearance of eye color, whether brown, hazel, green, gray, blue, or variations thereof.

For instance, brown eyes have a high amount of melanin, giving them their dark color. Blue eyes, on the other hand, have very little pigment. They appear blue due to light scattering, similar to why the sky looks blue.
Newborns often start with dark eyes, especially those with darker skin tones. As they grow, the pigment spreads and settles into what will likely be their permanent eye color by their first birthday.
Can we predict a baby’s eye color? Sort of. Using a tool called the Punnett square, we can estimate the probabilities. For example, two blue-eyed parents have a 99% chance of having a blue-eyed child. But there’s always that tiny chance for something different due to the hidden complexities of genetics.
Eye color can sometimes indicate health conditions too. Heterochromia, where a person has two different colored eyes, can be a sign of Waardenburg syndrome, which might also cause hearing loss.
There’s also ocular albinism, mostly affecting men, where the eyes have very little to no pigment, making them extremely light-sensitive. Aniridia is another condition where parts of the iris are missing, affecting vision.
So, while your baby’s eye color is a beautiful feature, it also tells a complex story of genetic inheritance and can sometimes hint at underlying health conditions.
That’s it for today’s deep dive into what decides your baby’s eye color. If you enjoyed this vblog, make sure to like, and subscribe for more fascinating insights into the world of science. Please check out our blog on latest and most effective treatment for HIV/AIDS in 2024 [Article].


  • Harden, Darby L., and Tasha B. Verdeyen. “The Baby Project.” Early Childhood Research & Practice 9, no. 2 (2007): n2. [Article]

By The Research Mind

We, researchers from the University of Oxford and University of Cambridge, are dedicated to sharing the latest updates, breakthroughs, and even the occasional blunders in Science & Technology. Stay tuned for some truly mind-blowing science experiments!

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