2. DISEASES AND DISORDERS OF THE SPECIAL SENSES

3. Presbyopia Lens loses ability to change shape Lens loses ability to change shape Usually caused by age Usually caused by age

4. Myopia (near sighted) Caused by eye shape being too long Causes light to focus in front of retina Corrected with glasses or contacts

5. Hyperopia (far-sighted) Caused by eye shape being shorter than normal Caused by eye shape being shorter than normal Causes light to focus behind the retina Causes light to focus behind the retina Corrected with glasses or contacts Corrected with glasses or contacts

6. Astigmatisim Caused by corneal malformation Caused by corneal malformation Creates a distorted image on the retina Creates a distorted image on the retina

7. Cataracts Caused by clouding of the lens Caused by clouding of the lens Can be replaced with artificial lens Can be replaced with artificial lens

8. Cataract

9. Conjunctivitis Caused by an infection of the conjunctiva More commonly called “pink eye”

10. Conjunctivitis

11. Glaucoma Aqueous humor build up puts pressure on the retina Aqueous humor build up puts pressure on the retina Can damage retina if not treated Can damage retina if not treated

12. Macular Degeneration Occurs in section of the retina called the macula damaged causing a dark area that progresses over time

13. Macular Degeneration

14. Strabismus Caused by weak eye muscles Caused by weak eye muscles Sometimes referred to as crossed eyes Sometimes referred to as crossed eyes Can be surgically corrected or by patching the good eye to encourage other eye to work properly Can be surgically corrected or by patching the good eye to encourage other eye to work properly

15. Deafness Two types: Two types: Conductive: caused by blockages in the auditory canal Conductive: caused by blockages in the auditory canal Can be blocked with ear wax Can be blocked with ear wax Can be caused by middle ear infections or Can be caused by middle ear infections or Eardrum damage Eardrum damage

16. Sensorineural deafness Sensorineural: Damage to auditory nerves Cochlear malformation or damaged by infection Brain damage in temporal lobe

17. Cochlear Implants

18. Middle Ear Infection Usually involves the eardrum being infected by bacteria or virus Bacterial treated with antibiotics Common in children Called Otis Media

19. Tinnitus Caused by improper discharge of electrical impulses of the Organs of Corti Hair cells Caused by improper discharge of electrical impulses of the Organs of Corti Hair cells

20. Vertigo Caused by otoliths improperly aligning with membranes Caused by otoliths improperly aligning with membranes May also be caused by middle ear infection moving into inner ear May also be caused by middle ear infection moving into inner ear Causes dizziness and nausea Causes dizziness and nausea

21. THE END!