Abstract: A display is provided having private and public viewing modes. The display comprises a display device and a parallax optic (3) comprising an array of parallax elements (4). Each of the elements (4) co-operates with a set of pixels (1,2) having at least one first pixel (1) and at least one second pixel (2). A line (23) passing through the centre (21) of each first pixel (1) and the centre (22) of the cooperating parallax element (4) extends into a first viewing region (20a). The parallax elements (4) re-strict viewing of the first pixels (1) to the first viewing region and permit viewing of the second pixels (2) in a second viewing region. The display device displays a private image in the private viewing mode by means of only the first pixels (1) and displays a non-private image in the public viewing mode by means of at least the second pixels (2).