A display device includes a display module emitting collimated light along a propagation direction and an adjustment panel disposed on the display module. The adjustment panel includes a first substrate, a second substrate, a medium layer disposed between the first substrate and the second substrate, a first electrode layer disposed on the first substrate, and a second electrode layer disposed on the second substrate and facing the first electrode layer. The medium layer includes a first medium. When the adjustment panel is in a first enabled state, a voltage difference exists between the first substrate and the second substrate to form an electric field distribution. At least one equivalent dioptric structure is formed in the medium layer according to the electric field distribution. At least part of the collimated light passes through the equivalent dioptric structure and emits along a predetermined light emitting direction deflected from the propagation direction.