1. Be able to diagram and explain the relationship between radiance, illuminance, luminance, and reflectance.

2. Have you ever heard of the anableps, the 4-eyed fish? It has two visual systems in a single eye, for seeing both above and below the waterline. Explain the concept of the duplex retina. What is the duplex retina? What is the evidence for having a duplex retina? Are we like the anableps?

3. In discussions about brightness, I said that the rule is "the coal is always black." Using two objects, like a piece of coal and my white- when-clean coffee cup, explain what this statement means with respect to illuminance, luminance, and reflectance.

4. What are Mach bands? Are Mach bands real or are they illusions?

5. Explain the concept of "lateral inhibition." Draw and explain a retinal circuit that shows how lateral inhibition could produce Mach bands.

6. Draw a portion of a Hermann grid. Explain the illusion seen. Explain the illusion according to a lateral inhibition explanation. Where is the illusion? Is what we see real or an illusion?

8. Explain the relationship between the spectrum, wavelength, and color. Why is purple considered such an important color?

9. Explain why a cow would look purple, using additive and subtractive color mixing.

10. Explain how the Munsell system works. Why do we need a Munsell system anyway?

11. Explain the development of trichromatic theory. What did Helmholtz do? What did he find?

12. Explain the development of opponent process theory. What did Hering consider to be the critical evidence?

13. Be able to draw and interpret the spectral sensitivity curves for the three types of cone receptors in humans. What are the "primary" colors according to the cones? Does this contradict our tendency to talk about red, yellow, green, and blue as being primary colors?

14. What is a dichromat? How many types of dichromats are there? How many dichromats do you need to change a lightbulb? Pick your favorite type of dichromat and explain their color experience using their cone spectral sensitivity curves.