Measuring visual fatigue and visual discomfort associated with 3-D displays

This research identifies methods of detecting signs of visual complaints associated with stereoscopic displays. Two potential causes for contradictory results concerning these signs in previous research are hypothesized: (1) not all clinical tests are equally appropriate, and (2) there is a natural variation in susceptibility amongst people with normal vision. An optometric screening differentiated participants with moderate binocular status (MBS) from those with good binocular status (GBS). In a 2 × 2 within-subjects design (2-D vs. 3-D and MBS vs. GBS), a questionnaire and eight optometric tests (i.e., binocular acuity, aligning prism, fixation disparity, heterophoria, convergent and divergent fusional reserves, vergence facility, accommodation response) were each administered before and immediately after a reading task. Results revealed that only participants with MBS in 3-D conditions showed clinically meaningful changes in fusion range, experienced more visual discomfort, and performed worse on the reading task. A combination of fusion range measurements and self-report is appropriate for evaluating visual complaints of stereoscopic stills, and people with a MBS are more susceptible to visual complaints associated with stereoscopic displays. A simple measurement tool, i.e., the ratio of reading performance between 2-D and 3-D, to categorize people based on their binocular status is proposed. Keywords — Visual discomfort, visual fatigue, stereoscopic displays, human vision, self-report, optometric measurement, performance measurement.