The human brain adapts to a constant stimulus of our neural system. For instance, if we ride a train and look out of the window for a long time and the train stops, we have the feeling of slowly moving backwards.
There are other, more extreme stimulus like a neave strobe as shown in this picture:
This particular animated image produces a rapid neural adaption causing us to see things moving for about 10 seconds. I have also observed that binaural beats cause minor ear ringing symptoms if listened to for a longer period of time.
The burning question here is: Can prolonged stimulus to such images or sounds cause Hallucinogen persisting perception disorder?