To suppress the increase in power consumption and suppress the decrease in display quality of a display device capable of displaying 3D images, whether each of optical shutters arranged in a matrix is brought into a light-transmitting state or a light-blocking state is selected in accordance with a voltage between a pair of electrodes (a first electrode and a second electrode) of the optical shutter. By control of the voltage between the pair of electrodes, a parallax barrier can be selectively formed in an intended region. Thus, a parallax barrier can be formed only in a region where 3D images are to be displayed.