An image display device includes a display panel which includes a plurality of pixels and operates in a 2D mode and a 3D mode, 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. Each of the plurality of pixels includes an upper display unit and a lower display unit, which are vertically disposed in a mirror form.