The eye and facial tracking technology incorporated in the Meta Quest Pro plays a significant role in research exploring visual attention, cognitive processes, user interaction, and human behavior analysis. However, differences in eye anatomy, such as Outer canthal distance (OCD), Interpupillary distance (IPD), and Intercanthal distance (ICD), may impact the accuracy & reliability of eye movement data. This preliminary study aims to evaluate the impact of inter-eye distance variations on eye-movement-based feature extraction in VR environments using the head-mounted device Meta Quest Pro. The data collection process involved the recruitment of 16 participants, comprising 10 males and 6 females, within the age range of 21 to 30 years. This specific range was selected to minimize inter-individual variability, enhance experimental control, and ensure consistency in cognitive and behavioral responses, given that reaction time, attentional regulation, and visual processing speed are known to vary with age. The process is followed by eye measurements (OCD, IPD, and ICD), an eye calibration test before the experiment, and 3 experimental tasks: fixed gaze task, regular eye movement task, and irregular eye movement task. The Meta Quest Pro recorded participants' eye movements while they performed VR-based tasks, followed by the extraction of eye-related features from the device. The dataset underwent Shapiro-Wilk, and D'Agostino-Pearson normality tests, followed by statistical analysis (Spearman Correlation, Kruskal-Wallis, and Mann-Whitney U test) to assess differences in eye-movement correlations across wide, narrow, and average eye distance groups. The results of statistical tests did not indicate a significant influence of inter-eye distance on eye movement tracking accuracy. Across all inter-eye distances, both Kruskal-Wallis and Mann-Whitney U tests showed no significant differences (all P ≥ .60), strong bilateral correlations were observed for all gaze features (Spearman ρ = 0.84-0.99), and spatial accuracy remained stable across groups, with angular error ranging from 1.11° to 1.36°.
Raza et al. (Sun,) studied this question.