Abstract: A stereoscopic viewing device to induce the line of sight of a viewer's eyes to converge on a three dimensional image formed from a pair of stereoscopic images. The device includes a pair of prisms and blinders to block out ghost images which form to the sides of the superimposed image. The device further includes adjustment means to narrow or widen the viewing window which the prisms form. One embodiment of the adjustment means includes blinders that are slidable panels within a guide track while another embodiment of the adjustment means are separate prisms slidable within a guide track.