The Projector Illusion |  EVERYDAY MYSTERIES

It´s not only projectors that rely on persistance of vision, the good old cathode ray tube also creates only parts of the image for a small fraction of time, but what you see is a complete image. Furthermore what´s also fascinating is the way how the brain controls the eyes´ movement. That includes an essential feedback signal that goes from the areas of the brain that coordinate the movement to the actual visual systems to prevent the image of the outside world from jumping around when changing your visual focus. This only works when the extraocular muscles are actively involved in moving the eyeball. Poking your eye with your finger (only through your eyelid!!!) will cause the image to tilt or skip, because the visual system doesn´t get the right feedback to correct for  the movement.