An image display device includes a display panel which includes a plurality of subpixels and selectively displays a 2D image and a 3D image, a patterned retarder for dividing light from the display panel into first polarized light and second polarized light, and a control voltage generator, which generates a first DC control voltage of an OFF-level and a second DC control voltage of a slight-on level, which is higher than the OFF-level and is lower than a full-on level, and selectively outputs the first DC control voltage and the second DC control voltage depending on a driving mode.