• Question: why is the human eye round like a circle? georgethedunn

    Asked by georgethedunn to Carol, Ellie, John, Philip, Rebecca on 3 Jul 2012.
    • Photo: John Welford

      John Welford answered on 3 Jul 2012:

      Well actually the eye is round in 3D, like a ball. The reason it is round is because that is the way it evolved, creatures/mutations with other shaped eyes weren’t as good and therefore didn’t survive.

      The next question is why is a round eye better, and I think the answer to that is because it is a shape that can rotate inside its container (the eye socket). This means we can move our eyes to look in different directions without moving our head. This would be a big evolutionary advantage as we could look out for danger more easily/quickly.

      It’s also worth mentioning that the lens of the eye is curved in order to focus light on the retina where it is detected. But the lens could be this shape without the eye being a ball. For example camera lenses are this shape but cameras aren’t ball shaped (as they would be much harder to hold!).

    • Photo: Rebecca Lacey

      Rebecca Lacey answered on 3 Jul 2012:

      It is not completely circular in fact. Take a look here: http://tinyurl.com/c8e4gdr

      You will see that the cornea bulges out the circle at the front of the eye. The shape of the cornea helps to focus light onto the retina at the back of the eye. The image that is perceived here is transmitted to the brain via the optic nerve.

      Take a look at this youtube animation of how the eye works and how its shape is key to its function:

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