title: Another optical-geometrical illusion.
abstract: A new optical-geometrical illusion is described. The parallelism of short rows of dots is affected by some unknown factor, so that the rows appear as pivoting on their middle point. Some explanations of the illusion are considered, but with no success.
mesh_terms: D006801:Humans; D007088:Illusions; D009903:Optical Illusions; D014796:Visual Perception