1. The Eye Structure

2. External Parts of the Eye (Tear Duct)

4. 1. Sclera White part of the eye Is made of tough tissue Protects the inner workings of the eye and gives the eye its shape

5. 2. Cornea The curved, clear, outer surface Covers the iris and pupil

6. 3. Aqueous Humor A clear, watery fluid Circulates in the front part of the eye, maintaining a constant pressure inside the eye.

7. 4. Pupil Is the opening in the center of the iris The size of the pupil: determines the amount of light entering the eye controlled by circular muscles

8. 5. Iris The colored part of the eye Made of circular muscles Controls the size of the pupil

9. 6. Lens A clear convex lens Is responsible for focusing light to form an image on the retina Can change shape to focus on nearby and distant objects

10. 7. Vitreous Humor A clear, jelly-like substance Fills the eye behind the lens Holds the structures of the eye in place Maintains the shape of the eye

11. 8. Optic Nerve A thick bundle made of millions of neurons Carries visual information from the retina to the brain.

12. 9. Retina A thin, translucent, light-sensitive tissue made of specialized cells called rods and cones Receives images formed by the lens

13. 10. Optic Disc The point where the optic nerve enters the retina NOT sensitive to light Known as the “blind spot”

14. 11. Tapetum A shiny layer that lines the area behind the retina of many animals Helps make animal eyes visible in the dark Allows them to see better at night

15. Vision

16. Corrective Lenses ( Glasses & Contacts) Near Sighted Far Sighted

17. Color Blindness Your eyes have special cells called rods and cones Rods – Light sensitive Cones – Color Sensitive

18. Color Blindness There are three main kinds of color vision defects. Red-green color vision defects are the most common. This type occurs in men more than in women. The other major types are blue- yellow color vision defects and a complete absence of color vision.

19. Color Blindness Most of the time, color blindness is genetic. There is no treatment, but most people adjust and the condition doesn't limit their activities.

20. LASIK 1. Create a flap of corneal tissue 2. Remodel the cornea using the laser 3. Reposition the flap