Parents with blue eyes: what colour will the baby's eyes be?
In this model, your baby will have blue eyes. In this simple model, brown eyes and green eyes are not possible, though real life can still surprise you.
Most likely eye colour
Blue
“Unlikely” means 0% in this model. In real life it can still happen, because many more genes shape eye colour.
Many babies are born with lighter eyes that darken during the first year. The colour has usually settled by the first birthday and can still shift a little until about age 3.
Estimate from a two-gene model that assumes each parent carries hidden versions of both genes.
A simplified estimate for fun. Real genetics is more complex.
How we work it out
The model uses two genes. bey2 has a brown version (B) and a blue one (b); gey has a green version (G) and a blue one (b). Each parent passes on one version of each gene, so each parent has four equally likely combinations and the square has 16 boxes. Any B gives brown eyes; otherwise any G gives green; otherwise the eyes are blue.
A blue-eyed parent has only blue versions of both genes: bey2 bb, gey bb.
| b b | b b | b b | b b | |
|---|---|---|---|---|
| b b | blue | blue | blue | blue |
| b b | blue | blue | blue | blue |
| b b | blue | blue | blue | blue |
| b b | blue | blue | blue | blue |
- Blue: 16 of 16 boxes
Frequently asked questions
Can parents with blue eyes have a baby with brown eyes?
Not in this simple model. Eye colour really depends on many genes, so it can still happen, but it is rare.
Can parents with blue eyes have a baby with green eyes?
Not in this simple model. Eye colour really depends on many genes, so it can still happen, but it is rare.
Can parents with blue eyes have a baby with blue eyes?
Yes. In this model every box of the square gives blue eyes.
- MedlinePlus Genetics (US National Library of Medicine): Is eye color determined by genetics?
- The Tech Interactive, Ask a Geneticist: What are the chances my child will have red hair and blue eyes?
- Eiberg H, Mohr J. Major genes of eye color and hair color linked to LU and SE. Clinical Genetics 1987;31(3):186-191
- American Academy of Ophthalmology: 20 Things to Know About Children's Eyes and Vision
- Jabbehdari S et al. Colour change in the newborn iris: 2-year follow-up of the Newborn Eye Screening Test study. Acta Ophthalmologica 2019