1. Disorders of the eye. Astigmatism Myopia - nearsightedness Hyperopia - farsightedness Presbyopia Color blindness Cataracts Glaucoma Conjuctivitis

2. Astigmatism Distortion of vision due to abnormal curvature of the cornea or lens Lenses can correct astigmatism

3. Myopia (nearsightedness) Common among young people - eyeball grows too rapidly during maturation & light is focused in front of the retina Can be corrected with the use of concave lens

4. Hyperopia(farsightedness) Light is focused behind the retina – Eye may be too short Can be corrected with a convex lens

5. Presbyopia Declining ability to accommodate Bifocals People who never needed glasses before may need convex lenses for reading

6. Color Blindness X linked trait; most often affects males Inability to distinguish between certain colors

7. Cataracts Loss of transparency caused when the lens becomes cloudy More common in older people Can be treated with surgery

8. Glaucoma Increased pressure on the optic disk due to build up of aqueous humor This can be treated one of two ways – Surgery of the Iris – Drugs that constrict the pupil

9. Conjunctivitis May be caused by smoke, dust, chlorine, bacteria, and viruses Most common in children may be treated with antibiotics