Acton belongs to the Space Division Constructions series, which James Turrell began in 1976. In these works, Turrell defines two distinct areas of a room: the "viewing space," where the audience stands to view the work, and the "sensing space," which is filled with diffused light. A thin partition with a large opening in its center separates the two spaces. Turrell creates an optical illusion in which the viewer initially perceives the opening as a flat, monochromatic surface. Prolonged viewing yields a surprising shift in perception, as the viewer may see and even reach into the sensing space.