Abstract: Compact periscopic device particularly adapted for vehicular rear vision, including an optical train to provide a wide field of view with optimum resolution and brightness and adapted to the confines of a relatively small housing enclosure. The optical train directs the incoming light rays through a series of direction reversals whereby the housing size requirements are considerably reduced. Further, the optical train consists of a pair of alternately operable, Fresnel-type objective lenses of differing focal length to provide for either a wide unit magnification of rear-viewed objects in one instance or a greatly expanded field of view in another instance. The optical train also includes image-reversing and image-inversion reflective surfaces, to correct for lens reversal and inversion of the image.