Flickering Fog Illusion

Just like you did for the other Illusions before, stare intently at the red dot in the center of the left block for about a couple of minutes. Once you've done this, look over to the center of the right block. It should act weird - by fading out and 'flickering'. If you move your head closer and further from the monitor (while focussing in the center), you should see some interesting interference effects too.