Color, Depth, and Size

For many people, color is a salient aspect of the visual world—it helps us separate objects from the background and it helps us detect danger. But not everybody can see color, and 5-10% of the population has “anomalous” color vision. This chapter discusses the uses of color, the causes of color blindness, the ways that color is encoded in the visual system, and finally, how flexible and context-dependent our perception of color is.

Size and distance are two things that are very hard to estimate for the visual system because they are interrelated. How do you know if you’re looking at a small object close to you or a big object far away? Distance is difficult for us to estimate, visually, because the 3D world is projected onto our 2D retina, and the brain has to use every clue it can find to figure out what the correct 3D interpretation of the world is.

This chapter was created by: Mohamed Ahmed, Molly Baugh, Francel Colon-Acosta, Jarod Davis, Kaelyn Dezell, Lucas Gaffney, Madelynn Gibbons, Trevor Graham, Katherine Hebig, Noah Hjelle, and Wanlin Hu