2. TO SEE OR NOT TO SEE THAT IS THE QUESTION

3. LIGHT  Travels in waves  ROYGBIV  Colors are different wavelengths of light

4. Color blindness test

5. EYE DIAGRAM 1. Cornea-window of the eye 2. Aqueous humor-holds cornea away from eye 3. Pupil-lets light in 4. Iris-controls amount of light 5. Ciliary body-controls iris 6. Lens-focuses light on back of eye 7. Vitreous body-gives eye shape 8. Retina-contains light sensitive nerves 9. Sclera-white of the eye-reflects light away 10. Optic nerve-brings message to brain 11. Fovea centralis-center of vision 12.

6. Retina  Contains nerves called rods and cones  Rods sense light and are very sensitive (low threshold)  Cones sense color but not very sensitive (higher threshold)

7. Function of Rods In rods there is a pigment called rhodopsin When a photon of light hits it, it breaks down into retinal and opsin  changing polarity and bringing a message to the brain if bright light is present, it takes time to replace the rhodopsin, bleaching occurs About 10,000 rods converge to one integrative neuron in the brain

8.  Three colors  primary colors of light  Lack of one or more=colorblindness  Center of vision (fovea) is all cones  Each cone has its own integrative neuron in the brain CONES

9. Cone densities and spectrum  Average adult has 16% blue, 74% red and 10% green cones

10. Back to visual cortex