There are optical illusions in the world that present things in way different manner than what they are in real. When we have full control on our mind to understand things making sense, there are some cases in which it goes out of control a bit and make us see things that are not real but perfect instances of optical illusions.
Stare in center at the dot and then move the sight away from it. You will notice rotation in the rings. Their direction gets changed if you get closer gradually
This optical illusion was found in 1870 by Ludimar Hermann. Looking at the intersection of white lines, a shadowy, gray blob is perceived by our eyes. However, the blob disappears when any of intersections is looked directly