Normal Eye Eyemac Home Tell me about the normal human eye. The human eye has many similarities to a camera both in its structure and function. There is a clear window at the front of the eye called the cornea, a coloured iris to control the amount of light, a lens for changing focus, and a retina or film to make the images. Remember that your retina is actually an outgrowth of the brain itself.
Visible light enters the eye by passing through the clear cornea.
The cornea actually does the majority of focussing of light. It also filters out most harmful UV radiation. Your cornea needs to be properly lubricated by the tear film secreted by tiny glands in your eyelids. It functions like the focus ring on your camera's lens. The light finally is absorbed by photoreceptors in the retina.