Motion aftereffect is a natural phenomenon that occurs when a person—after viewing movement in one direction for a time—sees motion in the opposite direction upon gazing at a stationary stimulus. Essentially, the illusion makes you see motion where there isn’t any, theorized to be the result of motion adaptation. When direction-specific nerve cells fatigue from continuous neural firing, hyperpolarization occurs and extracellular imbalances are created. When the moving stimulus is removed, the nerve cells responsible for the opposite direction work to balance the stimulus, resulting in the perception of movement.
This Video Plays Tricks on Your Vision
Screen Capture from Youtube video.