Despite many benefits that stereoscopic displays are known to have, there is evidence that stereoscopic displays can potentially cause discomfort to the viewer. The experiment reported in this paper was motivated by the need to quantify the potential subjective discomfort of viewing stereoscopic TV images. Observers provided direct subjective ratings of eye strain and quality in response to stereoscopic still images that varied in camera separation, convergence distance and focal length. Display duration of the images was varied between 1 an d15 seconds. Before and after the experiment, observers filled out a symptom checklist to assess any subjective discomfort resulting from the total experiment. Reported eye strain was on average around 'perceptible, but not annoying' for natural disparities. As disparity values increased reported eye strain increased to 'very annoying' and quality rating solved off and eventually dropped. This effect was most pronounced for the stereoscopic images that were produce using a short convergence distance. This effect may be attributed to an increase in keystone distortion in this condition. No significant effect of display duration was found. The results of the symptom checklist showed a slight increase in reported negative side-effects, with most observers reporting only mild symptoms of discomfort. Finally, our results showed that subjective stereoscopic image quality can be described as a function of reported eye strain and perceived depth.
IJsselsteijn, W. A., de Ridder, H., & Vliegen, J. (2000). Effects of stereoscopic filming parameters and display duration on the subjective assessment of eye strain. In J. O. Merritt, S. A. Benton, A. J. Woods, & M. T. Bolas (Eds.) (p. 12). https://doi.org/10.1117/12.384448