Jasper Johns, The Critic Sees, 1964, sculpmetal over platic with glass, Lent by the Artist, Philadelphia Museum of Art

Johns addressed the subject of perception as early as 1964. In a sculpture called The Critic Sees, he replaced the eyes behind a pair of eyeglass frames with talking mouths. Seeing and talking are equated. The bricklike shape of the sculpture seems to imply the limits of such modes of perception. The work is also a humorous visual pun on the art world.