Two factors in visual fatigue caused by stereoscopic HDTV images

As respects with visual fatigue caused from watching stereoscopic HDTV images, we found that when stereoscopic HDTV images were displayed within the corresponding range of depth of focus, and remained still in the depth direction, the degree of visual fatigue was almost the same as that induced by watching images displayed at the depth of the screen. However, when images were displayed outside the corresponding range of depth of focus, visual fatigue was clearly induced. Moreover, we found that even if images were displayed within the corresponding range of depth of focus, visual fatigue was induced if the images were moved in depth according to a step pulse function.