An apparatus for the formation of a visual sense effect comprises a first object A having a plurality of windows disposed around an axis of rotation C and a second object B so disposed as to show part thereof through the windows W of the first object A, with the first object A and the second object B adapted to be rotated relative to each other round the axis of rotation C. By virtue of the visual sense effect in vision, this apparatus allows an object of a polygonal shape to be perceived as though the object were repeating enlargement, contraction, deformation, and eccentric movement.