I would try to explain to them that there are two theories for this. When it comes to vision it is complex it has to deal with the retinas and tracking.

A friend knows you are taking this class. One day, they ask you: "why don't the objects in my visual field appear to move each time I slowly move my eyes?"

In lecture and textbook, you learned that if we are staring at something that is stationary, such as a couch, or a mountain range, our brain does not detect any motion even if our eyes are moving. How can you explain this to them? (Hint: consider Sherrington and Helmholtz's theories, as well as the function of the motion detectors)

The first is by Sherrington which as our textbook basic vision explains "proposed that we monitor the movements of our eye muscles and by comparing retinal image motion with eye muscle movement." ( 174). Basically our eye movements and memory but it comes from the eye not the brain. Then you have the Helmholtz theory which as the book says, "the comparison should be made with the signal from the brain that tells the eye muscle to move" (174). Which is similar but deals more with the system of the brain. Basically with Sherrington like if you stare at the ocean it would be moving because your eye or in the retina remembers the ocean and that it's waves and moves where as Helmholtz has the memory stored in the brain and it reminds the eyes.

RESPOND TO THIS DICUSSION.