Look at the following image in the centre, until the dots dissapear, then look around the image again, the dots will re-apear and some will be green. Hard to explain. Just do it!
		
		
	
	
	
		
			
		
		
	
EDIT: omfg!
This one is amazing
		
			
		
		
	
				
			
	EDIT: omfg!
This one is amazing