The document discusses the anatomy and physiology of the special sense of vision and the eye. It describes the structures of the eye such as the sclera, cornea, iris, retina and its neurons, lens, vitreous and aqueous humors. It explains how light is focused on the retina through lens accommodation and the pathways of the visual system from the retina through the optic nerve and tracts to the visual cortex. Accessory structures like the eyelids, lacrimal apparatus and extraocular muscles are also outlined. Important functions including pupil constriction and accommodation are summarized.

1. Special Senses Part One Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2. The SensesGeneral senses of touch

3. Temperature

4. Pressure

5. Pain

6. Special senses

7. Smell

8. Taste

9. Sight

10. Hearing

11. EquilibriumSlide 8.1Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

12. The Eye and Vision70 percent of all sensory receptors are in the eyes

13. Each eye has over a million nerve fibers

14. Protection for the eye

15. Most of the eye is enclosed in a bony orbit

16. A cushion of fat surrounds most of the eyeSlide 8.2Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

17. Accessory Structures of the EyeEyelids

18. EyelashesFigure 8.1bSlide 8.3aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

19. Accessory Structures of the EyeMeibomian glands – modified sebacious glands produce an oily secretion to lubricate the eyeFigure 8.1bSlide 8.3bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

20. Accessory Structures of the EyeCiliary glands – modified sweat glands between the eyelashesFigure 8.1bSlide 8.3cCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

21. Accessory Structures of the EyeConjunctiva

22. Membrane that lines the eyelids

23. Connects to the surface of the eye

24. Secretes mucus to lubricate the eyeSlide 8.4aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

25. Accessory Structures of the EyeLacrimal apparatus

26. Lacrimal gland – produces lacrimal fluid

27. Lacrimal canals – drains lacrimal fluid from eyesFigure 8.1aSlide 8.4bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

28. Accessory Structures of the EyeLacrimal sac – provides passage of lacrimal fluid towards nasal cavityFigure 8.1aSlide 8.4cCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings