For we have two types of vision–central and peripheral, not unlike the spotlight and the floodlight. Central vision is used for accurate work like reading, in which our eyes are focused on one small area after another like spotlights. Peripheral vision is less conscious, less bright than the intense ray of the spotlight. We use it for seeing at night, and for taking “subconscious” notice of objects and movements not in the direct line of central vision. Unlike the spotlight, it can take in very many things at a time.
