1. Cornea : The cornea is a thin membrane, which forms a transparent bulge on the surface of the eye ball. Maximum refraction of light rays entering the eye takes place from cornea.
2. Iris : It is a dark muscular diaphragm. The colour of iris is different for different people. It also controls the light entering the eye.
3. Pupil : It is a small opening of variable diameter at the centre of iris. It is useful to control and regulate the amount of light entering the eye.
4. Eye lens : It is a transparent biconvex crystalline body located just behind the pupil.
5. Retina : Retina is a light sensitive screen. It consists of large number of light sensitive cells called as rods and cones.
6. Optic nerve : Optic nerve is a carrier of signals from the retina to the brain.
