In the April 1971 issue of New Scientist magazine, Allan Neil present his new type of optical illusion…

Full scale research has not yet begun on the information-processing mechanisms which respond to the subtle factors in these illusions, but the preliminary studies have not overestimated their importance.

Here are 6 examples of these truly remarkable illusions…

Amazing, huh?

(via Ironic Sans, Lemon Harangue Pie)