EEG-Based Assessment of Stereoscopic 3D Visual Fatigue Caused by Vergence-Accommodation Conflict

Recent advances in 3D displays have contributed to the pressing need of new measurement methods for display comfort. Developing a valid measurement of visual fatigue caused by 3D display remains a big challenge and is beneficial for optimizing the system design. This paper assessed three electroencephalography (EEG) activities, θ, α and β, during a monotonous and repetitive random dot stereogram (RDS) based task in a conventional stereoscopic 3D display. Six types of ratio indices were computed based on EEG data and assessed as possible indicators for stereoscopic visual fatigue detection. The results of critical flicker frequency (CFF) and accommodative amplitude (ACC) showed that the proposed experiment setup can induce visual fatigue. According to the subjective ratings, the visual fatigue accumulated in this task was mostly related to the binocular vision stress of 3D display. Results of EEG data showed stable θ activity, a significant increase of α activity, and a significant decrease of β activity over time . In addition, the effectiveness of EEG indices was evaluated to measure stereoscopic visual fatigue by using grey relation analysis (GRA) and verified by correlating with CFF. The results of analysis suggest that among all nine types of EEG indices (θ, α, β, θ/β, α/β, α/θ, θ/(α+β), (α+θ)/β, (α+θ)/(α+β)), α is the most promising indicator for detecting stereoscopic visual fatigue.