How is baby eye color determined genetically?

Eye color is determined primarily by the OCA2 and HERC2 genes, though at least 16 genes contribute to the final color. Brown is generally dominant over green and blue, while green is dominant over blue. However, eye color inheritance isn't simple Mendelian genetics—two blue-eyed parents can rarely have a brown-eyed child, and two brown-eyed parents can have a blue-eyed child if both carry recessive blue alleles. The amount and distribution of melanin in the iris determines color: high melanin = brown, moderate = green/hazel, low = blue.

When do babies' eyes change to their permanent color?

Most babies are born with blue or grey eyes because melanin production in the iris is minimal at birth. Eye color begins changing around 6 months as melanin production increases, with most changes complete by age 1. However, eye color can continue changing subtly until age 3 or even later in rare cases. Eyes that start brown usually stay brown. Blue eyes at birth might turn green, hazel, or brown. The lighter the eye color, the more likely it is to change. Check eye color at 1 year for the most likely permanent shade.

Can two blue-eyed parents have a brown-eyed baby?

It's extremely rare but possible. If both parents are blue-eyed, they typically carry only recessive blue alleles and can't pass brown-eyed genes to their child. However, genetic mutations, additional eye color genes beyond the main two, or unexpected genetic contributions can result in different eye colors. Hazel or green eyes are more likely than brown in this scenario. Eye color genetics are complex—while blue-eyed parents will have blue-eyed children over 90% of the time, the genetics aren't 100% predictable.

How accurate are baby eye color predictors?

Baby eye color calculators provide probability estimates based on simplified genetic models, typically 60-80% accurate. They work best for predicting brown eyes (most common outcome) and less well for green or hazel (most complex genetics). Actual genetics involve multiple genes, modifier genes, and environmental factors. Use predictions as fun estimates, not certainties. Grandparents' eye colors can matter if parents carry recessive alleles. The only certain way to know your baby's eye color is to wait and see—usually by their first birthday.

Health

Baby Eye Color

Predict baby's eye color based on parents' genetics.

Brown

Green

Blue

How to Use This Calculator

Select Both Parents' Eye Colors

Choose the eye color for each parent from options: blue, green, hazel, or brown. Use the current, permanent eye color (not childhood color). If unsure between colors (like blue-green), choose the one that appears dominant in typical lighting.

Add Grandparents' Colors (Optional)

If available, select grandparents' eye colors for both sides. This information helps account for recessive alleles the parents might carry, improving prediction accuracy for less common eye colors.

View Probability Predictions

Review the percentage likelihood for each possible eye color outcome: brown, green, hazel, or blue. The calculator shows the most likely result and alternative possibilities with their probabilities.

Understand Limitations

Remember this is a probability estimate based on simplified genetics. Your baby's actual eye color depends on complex genetic interactions. Baby eye color typically becomes permanent around age 1-3, with the most significant changes in the first year of life.