A dual layer parallax barrier-based 3D display device may include an image panel that displays a left image and a right image so as to alternately display a left-image column and a right-image column, a dual layer parallax barrier that includes a first common electrode, a second common electrode, a plurality of first individual electrodes, a plurality of second individual electrodes, and a liquid crystal layer, and blocks specific portions of the displayed images and a driving unit that drives the electrodes based on the distance between the image panel and the viewer so as to allow the viewer to view the left image and the right image, separately, and simultaneously drives, in a particular state, at least one of the first common electrode and the plurality of first individual electrodes and at least one of the second common electrode and the plurality of second individual electrodes.