The Contribution of Stereoacuity to Cybersickness When Viewing 3D Films in Augmented Reality Head Mounted Displays

Abstract

Cybersickness remains a barrier to the adoption of augmented reality (AR) head-mounted displays (HMDs). AR HMDs present stereoscopic 3D (S3D) graphics that decouple the vergence and accommodation responses of the eyes. This decoupling produces a vergence-accommodation mismatch (VAM) that is implicated in cybersickness and visual fatigue. Because stereoacuity determines an individual’s sensitivity to binocular disparity, it may modulate how strongly VAM is experienced. However, existing evidence on the effect of stereoacuity on cybersickness and visual fatigue is mixed. The present study examined whether stereoacuity influences subjective cybersickness and visual fatigue and whether it influences oculomotor function post S3D viewing. Twenty-six participants, classified into HIGH and LOW stereoacuity groups using the TNO stereo test, viewed the first 30 minutes of an S3D film on the Microsoft HoloLens 2 while seated with the head stabilized in a chin-rest. Cybersickness (Simulator Sickness Questionnaire; SSQ) and visual fatigue (Visual Fatigue Questionnaire; VFQ) were assessed at baseline and every five minutes. Optometric measures assessed oculomotor function before and after exposure. Cybersickness and visual fatigue did not differ between the high and low stereoacuity groups but did increase significantly over the exposure. Oculomotor change over exposure was confined to metrics of vergence, including a receded near point of convergence but was unrelated to stereoacuity. A strong, positive correlation emerged between subjective cybersickness and visual fatigue. These findings indicate that stereoacuity is not a dominant factor in cybersickness during AR HMD use, and that managing exposure duration may be more effective than screening users on stereoacuity.