Association between the Level of Blurring and Depth of Field in Watching Stereoscopic Images

Abstract

Objective: The general explanation for visual fatigue with stereoscopic technology is that a mismatch of accommodation and convergence occurs during stereoscopic vision. Our previous studies measured lens accommodation and convergence simultaneously while subjects viewed stereoscopic video clips, and we found no discrepancy in young subjects. Since lens accommodation adjusts to the position of the virtual stereoscopic image, then the focus is not adjusted to the display surface, but to the virtual position. The question is whether or not a stereoscopic image might be blurred. We know that blurring is related to the changes in the depth of field which in turn is related to pupil diameter. We manipulated the luminance of displays and the environmental illuminance to affect the subjects’ pupil diameter to evaluate the level of blurring as subjects looked a visual acuity chart. The subjects were then asked to look at the same chart with various convex lenses to check if they could see a blurred image. We repeated this with a dimmed cover over the convex lens to measure the effects of darker conditions.