The eye might just be the most perfectly built part of your body. Evolved over millions of years, our human eyes give us some of the best vision, in terms of the balance of sharpness and colour, of any living thing.
There are a few main components in how your eyes work. The main thing to know is all vision depends on light. In the first step of seeing, light passes through your cornea and lens, which control focus. Next, the iris and pupil work together to control how much light enters the space inside your eye.
Once the right amount of light is focused in the right way, your retina – the layer of light and colour-sensitive cells at the back of the eyeball – is ready to receive it. The retina cells react to the light and send impulses down the optic nerve and to the brain. Your brain then instantly interprets all this information to build the ‘picture’ you see.
The Cornea is a curved dome of strong, clear tissue on the surface of the eye, the cornea focuses light onto the retina.
The epithelium provides a thin protective layer for the cornea and heals very quickly when disturbed.
The Iris is the coloured part of your eye and is actually a muscle that controls the size of the pupil.
The Pupil is the black circular area in the middle of the eye. It controls the amount of light reaching the retina.
The Retina is a membrane on the inner wall of your eye, similar to the film in a camera, the retina changes light into images that are transferred to the brain via the optic nerve.
The Sclera is the outer white coat of the eye, the sclera also provides protection.
The natural lens behind the pupil changes shape to allow the eye to focus. As you age, your natural lens hardens resulting in presbyopia-the loss of reading vision.