Impact of different optic flow patterns on vection and visually induced motion sickness

Abstract

This study investigates the impact of different optic flow patterns on vection and visually induced motion sickness (VIMS) in virtual reality (VR) environments. Vection, defined as the visual illusion of self-motion, can enhance VR experiences but is often associated with VIMS, which causes discomfort such as nausea and dizziness. This study systematically compares the effects of translational (forward/backward, lateral, vertical) and rotational (yaw, pitch, roll) optic flow patterns, along with comparing the effects of acceleration, using a virtual environment, assessing their influence on vection strength and VIMS severity. Data was collected from 73 university student participants. Results indicate that translational movements, particularly vertical motion, produced the strongest vection with minimal VIMS, while rotational movements, especially pitch and roll, caused severe VIMS but weaker vection. Acceleration was not found to be a significant factor. These findings highlighted an asymmetry in the effects of optic flow, suggesting that specific movements can enhance immersion while minimizing discomfort. The pilot study provides insights for VR developers aiming to balance user immersion with comfort, and facilitates future research on the relationship between vection and VIMS.