What I found to be intresting when reading was dark adaptation. Dark adaptation occurs when you are going from a light place to a dark place. When going from light to dark, it creates an increased sensitivity. The most basic example can happen at nighttime in your house when you go from a light room to a dark room. When you enter the dark room, at first you cannot see anything. As you continue to stay in the room, your eyes begin to adjust and as time goes on, you go from making out shapes to actually being able to see what is in the room. The that this occurs has to do with the cones and rods in our eyes. The cones are more sensitive to light and control the vision during the earliest stages of dark adaptation. As you go through time in dark adaptation the cones have done their job and the rods begin to take over. The rods do not take over until about 25 minutes. Once the rods begin to work, your eyes become able to adjust more to the darkness. A good example of this is the Mythbusters episode that they talk about in the book and that I have provided below (begin at 1:30). In the video they are testing out the myth of the eye patch used by pirates. The Mythbusters have the member of the group do the obstacle course coming into the dark from the light and coming into the dark after having an eye patch on. The member of the group after doing the course both times can notice an increase difference and the time is considerably better after using the eye patch. This shows that when an eye is adjusted to the dark that it can see better then when an eye is exposed to dark after light.