A stereoscopic display system comprises a layer of liquid crystal material (1) confined between two transparent electrodes (2 and 3) one of which is divided into a plurality of pixels A and B. The electrodes (2 and 3) and liquid crystal material (1) are confined between two linear polarisers (4 and 5) having polarising axes normal to one another. Furthermore a patterned half wave plate (20) is used comprising a region A' having an optic axis (21) orientated at -22.5 DEG to the polarisation axis (11) of the polariser (5) and the region B' having an optic axis (22) orientated at an angle +22.5 DEG to the polarisation axis (11). In order to view a stereoscopic image, viewing spectacles are provided having different polarising arrangements immediately in front of the viewer's two eyes, only the arrangement in front of the viewer's right eye (14) being shown and comprising a half wave plate (25) having its optic axis (26) orientated at -67.5 DEG to the polarisation axis (11) and a polariser (27) having its polarisation axis (28) orientated at 90 DEG to the polarisation axis (11). In use of such a system each of the viewer's eyes will receive substantially only light from a respective one of the pixels A and B, and a substantial improvement in achromaticity is possible as compared with known systems.