How the eye functions

In some ways the eye is similar to a colour video camera.

The iris or coloured part acts as the aperture of the "camera", regulating the amount of light reaching the inside of the eye. The clear window of the eye, or cornea, acts with the lens inside the eye to bend light rays and bring them to a point of focus on the retina.

The retina is a thin layer on the back of the eye and is sensitive to light like a photographic film. The image formed on the retina is then sent along the optic nerve to the brain.