1. VISION the sense we rely on most often

2. Photoreceptors in the eye are sensitive to wavelengths of light energy called the visible spectrum

3. Structures of the Eye

5. vitreous

6. Structures of the Eye iris vitreous

7. Structures of the Eye cornea vitreous iris

8. Structures of the Eye pupil vitreous iris cornea

9. Structures of the Eye lens vitreous iris cornea pupil

10. Structures of the Eye retina vitreous iris cornea pupillens

11. Structures of the Eye Optic nerve vitreous iris cornea pupil lens retina

12. Structures of the Eye

13. Function of Eye Structures

14. Lens – focuses the image on the retina Iris – pigmented muscle that give the eye its color and regulates the size of the pupil Pupil -- not a structure, but an opening in the iris Cornea – transparent portion of the sclera through which light enters

15. Function of Eye Structures Retina – layer containing photoreceptors that transduce light energy into a nerve impulse Rods – photoreceptors that are unable to detect color, but work well in low light Cones – photoreceptors that detect color in bright light but not in low light

16. Location of Rods and Cones CC

19. Function of Eye Structures The macula is located roughly in the center of the retina. It is a small and highly sensitive part of the retina responsible for detailed central vision. The fovea is the very center of the macula.

20. Vision Problems Glaucoma – pressure build up inside the eye causes damage (a leading cause of blindness around the world) Color Blindness – genetic deficiency in the cones, most common form is red/green color blindness (inability to distinguish between reds and greens) Cataracts – clouding of the lens

21. Vision Defects in Focusing Myopia = nearsighted due to an elongated eyeball Requires a concave lens to correct

22. Vision Defects in Focusing Hyperopia = farsighted due to a shortened eyeball Presbyopia = farsighted due to aging Farsightedness requires a convex lens to correct

23. Vision Defect in Focusing Astigmatism = due to a misshapen cornea, part of the image is focused and part is not Requires a non-symmetrical lens to correct