1. Let’s Get Visual!

2. What We See p. 125 Hue Visual experience specified by color names and related to the wavelength of light. Intensity Influences brightness and related to the amplitude of the light wave

3. An Eye on the World Cornea Protects eye and bends light toward lens. Lens Focuses on objects by changing shape. Iris Controls amount of light that gets into eye. Pupil Widens or dilates to let in more light.

5. The Structures of the Retina Cones (Fewer)Rods (More) Near foveaLocated in peripheral of the retina Responds to colorDark-adapted vision, scotopic More detail, higher resolution More sensitive to light, motion

7. Hubel & Wiesel’s Experiment Much visual processing is done in the brain. Feature Detectors Some cortical cells respond to lines in specific orientations Other cells in the cortex respond to other shapes

8. How We See Colors Young Helmholtz Trichromatic theory Opponent process theory

9. Trichromatic Theory Young (1802) & von Helmholtz (1852) both proposed that the eye detects 3 primary colors: red, blue, & green All other colors can be derived by combining these three.

14. Opponent-Process Theory A competing theory of color vision, which assumes that the visual system treats pairs of colors as opposing or antagonistic. Opponent-Process cells are inhibited by a color, and have a burst of activity when it is removed.

15. What’s Happening? In the retina of your eyes, there are 3 types of color receptors (cones) that are most sensitive to either red, blue or green.retinaeyes When you stare at a particular color for too long, these receptors get "tired" or "fatigued." When you then look at the white background, the receptors that are tired do not work as well. Therefore, the information from all of the different color receptors is not in balance and you see the color "afterimages." You can see that you vision quickly returns to normal.

16. Test of Color Deficiency