The eye - how we are able to see

The light entering our eyes passes through a 'window' of clear skin, through a lens and then forms a little picture ('the image') on the back surface of the eye. The back of the eye is made up of light sensors which are all connected to the brain using a nerve. As we grow up, the brain learns to understand what the information means and lets us move around and investigate the world.

Parts of the eye

The diagram shows the names of the different parts of the eye.

Two parts of the eye are designed to adjust so that everything can be seen clearly no matter what the conditions are.

The brain can control muscles to adjust the lens to make it thicker or thinner. This lets us see something which is close up and then change to viewing something far away.

In bright conditions the brain controls the size of the pupil to cut down the light entering the eye. This can be seen clearly by looking carefully at a friend's eye while switching on a light.