Question: what are eyes made of?

Rosie Coates answered on 7 Mar 2014:

Our eyes are very complicated! I can give you a one word answer to what they are made of though and that is cells, just like everything in our bodies.

The more complicated answer is that the eye is an organ, an organ is a collection of different tissues and a tissue is a collection of different cells doing different jobs.

The tissues of our eyes are arranged into 3 layers. The outside layer is called the fibrous layer. This layer has two parts- the first part of the layer you probably know as the whites of your eye, This is called the sclera. This part of your eye isn’t see through and it’s very hard so it can protect the rest of the more delicate layers inside. The very front of this outside layer is called the cornea and this part is see through. It helps us to bend light to make images of what we are looking at so we can see.

The middle layer is called the vascular layer and it is almost black in colour. This layer contains the muscles that help the lense of our eyes to flatten or thicken so we can make those images we need to see! These muscles also change the size of an opening called the iris to control the amount of light that is let into our eyes. This layer is also important as it brings blood to these muscles, as well as other parts of the eye, which gives then the oxygen and nutrients they need to do their jobs. Lastly, the dark colour of this layer is important as it stops light from bouncing around inside our eyes and messing up those all important images!

The last layer is called the retina. This layer acts as a screen where the images of what we are looking at are made by controlling all of the other parts of the eye. Your brain does this without you even realising!

Inside these three layers is a liquid called the aqueous humour which makes our eyes a round sphere and a gel called the vitreous humour.

This whole complicated description is of just one tiny part of your body! This is why science will never be finished! Our bodies are so complicated that we need people to keep on becoming scientists so we can keep on finding more and more out about how the work so we can have a better chance of fixing them when they don’t.