Averted vision works because there are virtually no rods (cells which detect dim light in black and white) in the fovea: a small area in the center of the eye. The fovea contains primarily cone cells, which serve as bright light and color detectors and are not as useful during the night.
Avoided vision functions because there are almost no rods (cells that detect dim light in black and white) in the fovea: a small area at the center of the eye. The fovea is primarily composed of cone cells, which serve as bright light and color detectors and are not effective during nighttime.