Eccentric Gaze

Let the eyes lie still so the pupils face forward. Don't rotate the eyeballs at all. Attend to the left without moving the actual eyeball (or head). That is peripheral vision. It means you're using the "sidewalls" of the back of your eyeball, the more rod-rich part, to see. At this point, the position of your eyeballs is not eccentric, but your gaze is. You attend to the left, but not by orienting your eyeball in that direction.