http://www.patmedia.net/marklevinson/cool/cool_illusion.htmlThis is a hard one to explain...
You stare at the cross in the middle and in your perifria, you see diffuse pink dots dissapear and reappear. Â It happens succesfully and quickly. Â You see the green dot replace the pink dot because you brain thinks the pink dot is still there, and your eyes see grey. Â The resultant is a greenish hue. Â If you stare long enough...the dots dissapear. Â This is the one that is hard to really explain because, as far I've read (and I do read up on neurology 'cause it's wicked interesting) no one is positive why. Â Persistant states tend to dissapear. Â Kind of like the Jurassic Park raptors only seeing you if you move. Â The dots are very visable at first, but since you mind is recieveing the same image pattern over and over again it will ignore that sensory input in order to concentrate on other visual cues. Â So, in saying that it is very important to keep you eyes on one spot and to not move your head around. Â If you notice, any slight movement and the dots come back into view.