An auto stereoscopic display device comprising: an image forming means having a two-dimensional array of display pixels for producing a display, the display pixels being spatially defined by an opaque matrix; and a view forming module arranged over and in registration with the image forming means, the view forming module comprising at least two optical means being a view forming means and a brightness non-uniformity reducing means (121 and 123), wherein the view forming means is adapted to modify the direction of outputs of the display pixels such that the outputs of groups of the display pixels are projected in respective different directions as a plurality of views, the view forming means being provided by an array of parallel view forming elements in the form of lenticular lenses extending in the column direction, wherein the lenticular lenses are arranged across the view forming module and have a first pitch, and wherein the brightness non-uniformity reducing means is located with a separation from the plane of the display pixels and adapted to spread the outputs of the display pixels such that brightness non-uniformities that would otherwise be caused by imaging of the opaque matrix are reduced, the brightness non-uniformity reducing means defining a second pitch across the view forming module of zero or less than the first pitch, characterized in that each of the lenticular lenses defines a curved focal surface having a focal point for normally incident collimated light which coincides with the plane of the display pixels, and the brightness non-uniformity reducing means further defines an effective spreading angle in a plane perpendicular to axes of the view forming elements in the range of 0.5 to 1.5 times the angle that would exist between adjacent views projected by the view forming means in the absence of the brightness non-uniformity reducing means. an image forming means having a two-dimensional array of display pixels for producing a display, the display pixels being spatially defined by an opaque matrix; and a view forming module arranged over and in registration with the image forming means, the view forming module comprising at least two optical means being a view forming means and a brightness non-uniformity reducing means (121 and 123), wherein the view forming means is adapted to modify the direction of outputs of the display pixels such that the outputs of groups of the display pixels are projected in respective different directions as a plurality of views, the view forming means being provided by an array of parallel view forming elements in the form of lenticular lenses extending in the column direction, wherein the lenticular lenses are arranged across the view forming module and have a first pitch, and wherein the brightness non-uniformity reducing means is located with a separation from the plane of the display pixels and adapted to spread the outputs of the display pixels such that brightness non-uniformities that would otherwise be caused by imaging of the opaque matrix are reduced, the brightness non-uniformity reducing means defining a second pitch across the view forming module of zero or less than the first pitch, characterized in that each of the lenticular lenses defines a curved focal surface having a focal point for normally incident collimated light which coincides with the plane of the display pixels, and the brightness non-uniformity reducing means further defines an effective spreading angle in a plane perpendicular to axes of the view forming elements in the range of 0.5 to 1.5 times the angle that would exist between adjacent views projected by the view forming means in the absence of the brightness non-uniformity reducing means.