The eye would get light from the objects which is by the sensory nerves and then the message would be sent to the coordinator and then the motor nerves would sent the message to the effector for us to decide about the object by the responses from the muscle. The cornea is the curve band 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 : The coloured part of the eye is actually a muscle that controls the size of the pupil. The pupil: The black circular area in the middle of the eye controls the amount of light reaching the retina. The retina: A membrane on the inner wall of the eye, similar to the film in a camera, the retina changes light into images that are transferred to the brain via the optic nerve. Sclera: The outer white coat of the eye, the scelera also provides protection. Lens: Is behind the pupil changes shape to allow the eye to focus. As a result of aging, the natural lens hardens, resulting in presbyopia, the loss of reading vision.