Jesús Rafael Soto's work is marked by visual tricks and optical illusions in the Op Art style. Soto's chief works include his 'Vibrations', thin metal rods lined up before a striped, two-dimensional background. Depending on the angle of view, the interplay of the arrangement of wires and striped surface creates different, almost hypnotic effects. In the year 1964, Soto exhibited a number of his 'Vibrations' at documenta III in the department for light and movement. His space-filling so-called 'Penetrables' made the viewers merge into the work of art as they strode through it.