Enhancement of the contrast ratio of optical flat panel displays by integrating an array of corner-cube retroreflectors into the front face of the optical display, said integration involving mutual adaptation of both the display and the corner-cube retroreflector geometry to unite the two disparate optical systems. The light emission from the display passes through the truncated vertex of the corner-cubes to the observer. The display directs its emitted light through the vertex apertures (either as a natural behavior, or by interposing a registered array of light concentrators between the display and the corner-cube array). The improvement in contrast ratio arises due to the corner-cube retroreflectors' ability to direct incident ambient light directly back to its source, rather than the viewer's eyes. Ambient light reflections are not attenuated but maximized; this maximization is directed away from the viewer, causing the array to appear dark even in direct sunlight.