It works a bit like a camera and is damaged just as easily. It is housed in a tough, protective wrapper called the sclera. This is sometimes called the white of the eye. At the front of the sclera is a transparent window which allows light to pass through. This window is called the cornea.
Light passes through the cornea and then through a hole, called the pupil.
This is the black spot at the front of the eye. The pupil changes size to allow different amounts of light to pass through. In dim light it opens up very wide to allow in as much light as possible. In bright light it becomes very small to stop too much light getting in. The muscle that controls the size of the pupil is called the iris.