Accommodation responses to horizontal-parallax-only super multi-view display

Super multi-view (SMV) displays have been developed to solve the vergence-accommodation conflict that causes visual fatigue with conventional three-dimensional (3D) displays. An ideal SMV display should generate dense viewpoints in both the horizontal and vertical directions. However, the SMV displays developed so far generate dense viewpoints only in the horizontal direction because of the system complexity required for full-parallax systems. Therefore, the accommodation responses to SMV displays were measured mostly for 3D images that contain distinctive vertical edges. In this study, we investigated the influences of the edge properties contained in 3D images upon the accommodation responses evoked by horizontal-parallax-only (HPO) SMV displays. We used the recently developed reduced-view SMV display, whose interval of viewpoints was 2.6 mm, for the accommodation measurements. Two test images were used: a "Maltese cross", which contains several sharp edges, and a standard test image of "Lenna", which contains various types of edges. We found that the HPO-SMV display still evoked the accommodation responses when "Lenna" was displayed. There were two types of accommodation responses for "Lenna"; the amounts of the evoked accommodation were smaller than or similar to those for the "Maltese cross", depending on where the viewers gazed.