A display device is disclosed. The display device may include a display panel, a light blocking member, a distance sensing member, and a controlling member. The display panel may include a pixel region and a transmission region. The light blocking member may be disposed on a rear surface of the display panel and have an adjustable light transmittance. The distance sensing member may sense a viewing distance between a viewer and the display device. The controlling member may calculate a proper viewing distance range, may compare the viewing distance with the proper viewing distance range to generate a comparison result, and may adjust the light transmittance of the light blocking member based on the comparison result.