• Question: how do our eyes see different colours and shades?

    Asked by anon-177128 to Urslaan, Nicola, Helen, Daniel, Becky, Andrew on 16 Jun 2018.
    • Photo: Andrew Singer

      Andrew Singer answered on 16 Jun 2018:


      You have rods and cones in your eyes which respond to different wavelengths of light and this gets communicated to your brain and interpreted as colour. That’s the short version. It’s worth knowing that our brain plays an important role in this…check out this webpage and you’ll know what I mean: http://www.bbc.co.uk/guides/zgh34j6

    • Photo: Becky Thomas

      Becky Thomas answered on 17 Jun 2018:


      What Andrew said… I couldn’t have worded it better!

    • Photo: Urslaan Chohan

      Urslaan Chohan answered on 18 Jun 2018:


      I’ll refer you in part to my answer here: /healthycitiesj18-zone/2018/06/17/why-do-most-things-have-colouring/#comment-611. To summarise it, light is a mixture of many colours (red, orange, yellow, green, blue, indigo, violet). The colours are separated by what is known as wavelengths. Different wavelengths are absorbed by an object of a certain colour, and the wavelength that is reflected back corresponds to the colour of the object (e.g. blue wavelength for a blue object). The reflected light enters our eyes through the pupil, passes through the lens that bends it onto the retina. The retina contains (as Andrew mentioned) cone and rod cells. Cone cells process colour, and they work a bit like a TV – some cone cells process red colour, whilst others process blue and green. These are primary colours (often shortened to RGB). The cells get activated when light of that frequency hits them, and send a signal to the brain through the optic nerve. The brain then processes the colour.

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