0. Be very clear on use of terminology. When am I describing the physics of the situation and when am I describing the psychological experience?

1. Know the definition of and the relationship among the terms: radiance, illuminance, luminance, reflectance, and brightness.

2. Understand the basic physics of how and where light rays from an object end up in your eye.

3. Be able to describe the structures of the eye and the retina from the standpoint of a photon entering the eye. What is the function of those structures?

4. Where are the photoreceptors located in the retina? How evenly are the photoreceptors distributed in the retina? How likely is a photon to hit a photoreceptor?

5. In discussions about brightness, I said that the rule is "the coal is always black; the chalk is always white." Using two objects, like a piece of coal and a piece of chalk, explain what this statement means with respect to illuminance, luminance, and reflectance. Can I predict the amount of brightness if I know how much light energy is coming from an object? (Reminder: What is the definition of brightness?)

6. What is our duplex retina? What is the shape of the dark adaptation curve? The Purkinje shift? What is the evidence for having a duplex retina? What does it mean to have a duplex retina?

7. Understand how "lateral inhibition" works in horseshoe crab vision.

8. Understand how "lateral inhibition" applies to  the Simultaneous Contrast Illusion, Mach bands, and the Hermann Grid illusion. Where is the illusion located in the Hermann Grid illusion? Is what see in the Hermann Grid real or an illusion?

9. Explain the Simultaneous Contrast Illusion. Is it an illusion or is it real? Where is the illusion in the simultaneous contrast illusion? What does the effect tell us about the function of the visual system?

10. What is the relationship between wavelength and color? What are spectral colors? Nonspectral colors? Metamers?

11. Is white a color? Is white a wavelength? Is purple a color? Is purple a wavelength? Is yellow a color? Is yellow a wavelength?

12. What is the difference between hue, saturation, and brightness? What is the difference between hue and color? How many colors can we see?

13. Understand how additive and subtractive color mixing work in daily life. Explain how to make a T-shirt look purple, using additive and subtractive color mixing. Where do we encounter additive and subtractive color mixing in daily life?

14. Understand trichromatic theory. What did Helmholtz do? What did he find?

15. Understand opponent process theory. What did Hering consider to be the critical evidence supporting his hypothetical color receptors?

16. Whose theory was correct, Helmholtz or Hering?

17. Know the location and shape of the spectral sensitivity curves for the three types of cone receptors in humans. Why do we label the cones as Short, Medium, & Long wavelength detectors instead of Blue, Green, and Red detectors?

18. At the level of activity of the cones, how do we explain seeing white, blue, purple, yellow, and green?

19. What causes color blindness? Identify the three types of color blindness. What is the physiological problem? What happens to the color world of individuals with each type of color blindness? How are dichromats similar to and different from trichromats?