The best for me [b]Hermann Grid Illusion[/b] [img]http://listverse.files.wordpress.com/2007/09/232px-hermann-grid-illusion.svg-tm.jpg?w=300&h=300[/img] [i]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.[/i]