the eye

• the main parts of the eye are: the sclera, cornea,optic nerve, retina, iris, pupil, cilliary muscles, suspensory ligaments and the lens
• the sclera is the tough, supporting wall of the eye
• the cornea is the transparent outer layer found at the front of the eye. it refracts light into the eye
• the iris contains the muscles that allow it to control the diameter of the pupil and therefore how much light enters the eye
• the lens focuses the light onto the retina
• the shape of the lens is controlled by the cilliary muscles and suspensory ligaments
• the optic nerve carries impulses from the receptors on the retina to the brain
• the iris reflex is the pupil constricting when light hits the retina
• when the circle muscles in the eye contract, the amount of light entering the eye is reduced