Binocular Fusion Ranges and Stereoacuity Predict Positional and Rotational Spatial Task Performance on a Stereoscopic 3D Display

In this work, we tested 12 participants on a virtual object precision placement task while viewing a stereoscopic 3D (S3D) display. Optometric measures of binocular function were obtained, including measurements of distant and near phorias (horizontal and vertical) and distant and near horizontal fusion ranges, using standard clinical techniques. Before each of six 30-min experimental sessions, measurements of phoria and fusion ranges were repeated. All participants completed experimental sessions in which the task required precise positional and rotational alignment of a virtual object in depth, at the same location and orientation as a stationary target object. The object was controlled by participants´ spatial manipulation of a wireless 6 degree-of-freedom (DOF) tangible user interface utilizing magnetic spatial tracking. Subjective discomfort was assessed using the Simulator Sickness Questionnaire (SSQ). Individual placement precision in S3D trials was significantly correlated with several of the binocular measures: viewers with larger convergent fusion ranges, larger divergent fusion ranges, larger total fusion ranges, or lower (better) stereoscopic acuity thresholds were more accurate at the task. None of the optometric measures were predictive of individual subjective discomfort, although a combined analysis with a similar previous experiment suggested that a personal history with motion sickness was related to discomfort levels from S3D viewing. The results confirm and extend previous research, suggesting that several key optometric measurements are predictive of complex manual spatial task performance on an S3D display system.