[The Godfather]

The Hermann Grid Illusion is an optical illusion reported by Ludimar Hermann in 1870 while, incidentally, reading John Tyndall's Sound. The illusion is characterised by ghostlike grey blobs perceived at the intersections of a white (or light-colored) grid on a black background. The grey blobs disappear when looking directly at an intersection.







The Orbison Illusion is an optical illusion that was first described by the psychologist William Orbison in 1939. The bounding rectangle and inner square both appear distorted in the presence of the radiating lines. The background gives us the impression there is some sort of perspective. As a result, our brain sees the shape distorted. This is a variant of the Hering and Wundt illusions.