• Question: Why are my eyes brown?

    Asked by anon-22966 to Amy, Karen, Sarah, Vijay, Will on 18 Jun 2012. This question was also asked by emily148, meg123, olivia13, nilokoko, ciaragrimesxox, niamhcarr.
    • Photo: Amy Birch

      Amy Birch answered on 18 Jun 2012:

      Hi cassie,
      The colour of your eye comes from the amount of melanin that is in your eye (this is the same thing that makes your skin darker or is in freckles). This can be in the form of yellow or black melanin. If you have no melanin in the front part of your eye, you have blue eyes. If you have different proportions of yellow and black melanin, you have different colour eyes ranging from hazel, brown, blue and green.

      Eye colour is something that you inherit from your parents, it is a polygenetic trait (which means that there is more than one gene that can affect the colour). This means that there are a number of genes that control how much yellow and black melanin you have and you will inherit these genes from your parents. Depending upon which ones you inherit from your mum and which ones you inherit from your dad, your eye colour will be more like your mum’s or your dad’s, or a new combination!
      Hope this answers your question 🙂

    • Photo: Sarah Martin

      Sarah Martin answered on 20 Jun 2012:

      Hi cassie!

      There are two things that shape eye colour – Amy has already explained the first, which is the genetically determined melanin production, and the other by how the light reflects from the iris of your eye. The second effect is officially called Rayleigh scattering, and is the same physics that makes the sky look blue and the sunset pink! So color also varies depending on the lighting conditions, especially for lighter-colored eyes! Neither blue nor green pigments are ever present in the eye, so those colours are made purely by the structure of the iris and the way it scatters light back.

      Are your eyes a different colour in different light?

      🙂
      Sarah

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