Real 3D increases perceived depth over anaglyphs but does not cancel stereo-anomaly

BackgroundAbout 30% of the population has difficulties detecting the sign and the magnitude of binocular disparity in the absence of eye movements, a phenomenon called stereo-anomaly. The stereo-anomaly tests so far are based on disparity only (e.g. red–green stereograms), which means that other depth cues cannot be used and even provide conflicting depth information.ObjectiveHere we investigate whether stereo-anomaly also occurs using a “true-3D” display which provides other depth cues that are all consistent with one particular distance in depth. Secondly, we examine differences in depth perception between red–green (anaglyphic) and true-3D displays. Finally, we test the displays’ relative viewing comfort.MethodSixteen observers (four of which were stereo-anomalous) judged the distance in depth between a fixation square and one or two bars. They were presented on an anaglyphic and a true-3D display, both in the fovea and 5 deg in the visual periphery. Observers were asked about the viewing comfort of both displays.ResultsStereo-anomalous observers also showed difficulties in perceiving depth with the true-3D display. Yet the true-3D display increased the perceived depth range compared to the red–green display for practically all observers at both eccentricities. All observers reported greater viewing comfort for the true-3D display.ConclusionStereo-anomaly is a robust phenomenon. True-3D displays improve depth perception and viewing comfort, most likely because retinal blur provides depth information consistent with disparity.ApplicationThe true-3D display shows potential for clearly and comfortably displaying objects at different depth planes.