The Non-Existing Co-Existence
At first glance every thing looks O.K. But, at second glance, there is some
cognitive dissonance

Sandro Del-Prete, among the greatest illusionists, demonstrates below how 1/2+1/2 does not always equal 1. Each 1/2 of the picture stands by itself whereas the combination is mutually exclusive.

The Columns by S.Del-Prete The Deformed Chessboard by S.Del-Prete

The Missing Eyes of Rene Magritte by A.Tamir