Cornea: The crystal clear dome that covers the front of the eye.

Lens: The crystalline lens focuses the light. It is able to change shape to allow focus on near objects. When it becomes cloudy it is called a cataract.

Iris: This is the part of the eye that gives it color (i.e., blue, green, brown).

Pupil: This is the opening in the middle of the iris. It expands and contracts to adjust for brightness. In a dark area, the pupil expands to collect more light.

Retina: This is a thin layer of nerve tissue that senses light. Specialized cells called rods and cones convert light energy ito nerve signals that travel through the optic nerve to the brain. The retina is analogous to the film in a camera.

Fovea: This is the center of the retina that receives the focus of the object of regard. Nerve cells are more densely packed in this area, so images that are focused on the fovea can be seen in greater detail.

Optic nerve: This is the nerve that runs from the eyeball to the brain. It carries information from the retina to the brain for interpretation.