1. 6. Ciliary muscles --
system of muscles that attach to the periphery
of the lens that changes its shape.
7. Vitreous humour --
transparent jelly-like material that maintains
the eyeball's shape.
8. Retina --
photosensitive cells that line the back of the eyeball.
Light is converted to electricity.
9. Fovea --
center of the retina. point of most acute vision.
10. Optic nerve --
nerve that sends electrical messages to the brain.

3. (Myopia) can see near but not far.
Eye Defects
1. Nearsightedness
(Myopia) can see near but not far.
Result of a long eye ball.
Fix: diverging lens
Either with glasses or contacts.
Or with LASIK surgery

4. 2. Farsightedness
(Hyperopia) can see far but not near
Result of a short eyeball
Fix: converging lens
Either with glasses or contacts.
Or with LASIK surgery

5. 3. Astigmatism
Can’t focus well at any distance
Result of a cornea that is asymmetrical
Fix: cylindrical lens
Either with glasses or hard contacts or soft
contact lenses called torque lenses.
Or with LASIK surgery

7. Result of a non-transparent lens
4. Cataracts
Pupil looks milky
Result of a non-transparent lens
Causes: hereditary, U-V exposure
Fix: removal of lens through surgery

14. 5. Glaucoma
disease of the optic nerve
Result of pressure build-up of Aqueous Humour
tends to happen over long periods
No cure. Is ususally treated with drops to reduce
pressure
marijuana can be prescribed.

16. Result of protein deficiency
6. Kerataconus
disease of the cornea
Result of protein deficiency
cornea weakens and grows to cone shape
hard contact lenses can be worn at first
if it progresses too much cornea transplants
must be done

17. Result when blood vessels enlarge and cause the Retina to detach.
7. Macular Degeneration
disease of the retina
Result when blood vessels enlarge and cause the
Retina to detach.
Affects the central vision first
Is usually treated with drugs
Macular degeneration electronic fix

18. 8. Night-blindness
disease of the retina
Retina lacks “rod” cells that give us night vision
No cure

19. disease of the retina
8. Colour-Blindness
Results from a lack of one or more cone cells
Person tends to confuse colours
Most common is Red-Green
Affects about 1 in 10 males and 1 in 400 females.