• Question: What are the chances of me having a completely different eye colour than my parents

    Asked by auks493med on 8 Nov 2023.
    • Photo: Martin Minarik

      Martin Minarik answered on 8 Nov 2023:

      I don’t know the exact percentages, so you might want to do a bit of research into that, but eye colour is influenced by quite a few genes with complicated interactions between them. So it’s not that two blue-eyed parents can’t have a brown-eyed child for example. They usually do, but not always.

    • Photo: Michael Schubert

      Michael Schubert answered on 9 Nov 2023:

      That depends on your eyes, your parents’ eyes, and sometimes even the eyes of earlier generations! Eye colour is (mostly) genetic, but because – as Martin said – there are a number of genes and interactions that can influence it, it can be quite complicated to work out the chances of your specific eye colour coming from two people with your parents’ specific eye colours. There are also some genetic conditions (and even injuries) that can affect eye colour, which makes things even more complicated!

      Here’s an article you can read about it if you’d like:

    • Photo: Eleonora Roschi

      Eleonora Roschi answered on 9 Nov 2023:

      Many aspects of your body are combinations of many people before you. For example, I am exactly as tall as my mum, but I have my dad’s eyes. I also share some things with my grandparents that my mum and dad don’t have. Eye colour is a result of many genes working together, and these come from all your ancestors. It is very difficult to calculate the chances, but you can do some estimations based on the characteristic in your family members 🙂

    • Photo: Martha Mulongo

      Martha Mulongo answered on 10 Nov 2023:

      I agree with the existing responses. This has to be considered that it has to be existing in your lineage from grand parents. Many genes are interacting to bring about the existing feature. Considering the fact that some genes are recessive and some are dominant.

    • Photo: Martin Johnsson

      Martin Johnsson answered on 11 Nov 2023:

      I wish I had a good number to give you, because this is a question that could–in principle–be assigned a percentage number. “If your parents have eye colours A and B, your probability of getting eye colour C is …” but it would:

      1. depend on what colours A, B and C we are talking about
      2. be quite uncertain, because the inheritance of eye colour is quite complicated, and our estimates of the probabilites would not be perfect.

      Eye colour is interesting because its inheritance is relatively simple, i.e. there are a few particular genetic variants in the genome that have a large influence on your eye color. But at the same time, it’s not that simple! Because there are several variants, and some evidence that they interact.

      So if someone tells you that eye colour is “Mendelian”, and determined by one single genetic variant, where blue is recessive and brown is dominant, you should respond by asking them “what about green eyes?”


    • Photo: Lucy Carver

      Lucy Carver answered on 13 Nov 2023:

      That depends on your parents eye colour! There are dominant and recessive genes. One of your parents could have one dominant gene for brown eyes and one recessive gene for blue eyes. This means they would have brown eyes but you could have blue eyes if you also inherited a blue eye gene from the other parent! Punnet squares help to make sense of these things

    • Photo: Nikoleta Vavouraki

      Nikoleta Vavouraki answered on 27 Nov 2023:

      Usually, if both parents have brown eyes, then the child will also have brown eyes. The gene that makes eyes brown can sometimes make a gene that makes eyes green or blue be “covered”, so this person would also have brown eyes. But if two people with “hidden” genes for green eyes have a child there is a chance that the child’s eyes will be green.
      However, a lot of unexpected things can happen randomly in biology, so we are rarely 100% sure of what the eye color of a child might be.