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

Background: About 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. Objective: Here 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. Method: Sixteen 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. Results: Stereo-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. Conclusion: Stereo-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. Application: The true-3D display shows potential for clearly and comfortably displaying objects at different depth planes. 2010 Published by Elsevier B.V.