A switchable autostereoscopic display device comprises a display panel having an array of display pixels for producing a display, the display pixels being arranged in rows and columns; and an imaging arrangement for directing the output from different pixels to different spatial positions to enable a stereoscopic image to be viewed. The imaging arrangement is electrically switchable between at least three modes comprising a 2D mode and two 3D modes. The imaging arrangement comprises an electrically configurable graded index lens array. The display can be switched between a number of modes to enable the display to be adapted or to adapt itself to the image content to be displayed and/or the display device orientation.