EntityQ2661088· pop 12· linked from 126 articlesOrbison illusionSign in to saveoptical illusionConnectionspsychologyEntityInternational Standard Book NumberEntitycircleEntitysquareEntityopticsEntityrectangleEntityellipseEntityillusionEntityoptical illusionEntityop artEntitytrompe-l'œilEntityambigramEntityPenrose triangleEntitycylindrical coordinate systemEntityPenrose stairsEntitygravity hillEntityconcentricEntityAmes roomEntityNecker cubeEntityafterimageEntityCategoriesOptical illusions