A reconfigurable parallax barrier panel comprising an electro-optic material has first and second regions. The parallax barrier panel is configured in a first mode to address the first and second electrodes on the basis of at least one received drive signal such that: the first electrodes define, in the first region of the panel, a first parallax barrier array selected from a plurality of predetermined parallax barrier arrays; and the second electrodes define, in the second region of the panel, independently of the first parallax barrier array, a second parallax barrier array selected from the plurality of predetermined parallax barrier arrays, the second parallax barrier array being different to the first parallax barrier array. To obtain a good autostereoscopic 3-D viewing zone the pitch of a parallax barrier would ideally vary over the width of the parallax barrier panel as a function of viewing distance. This is impracticable to obtain in a practical parallax barrier panel, but the present invention can provide a change in barrier pitch at the boundary between the first region and the second region, and this effectively mimics a pitch that varies over the width of the parallax barrier panel as a function of viewing distance. A parallax barrier panel of the invention can provide improved 3-D viewing when the parallax barrier panel is incorporated in a display.