Advantages of eye-gaze over head-gaze-based selection in virtual and augmented reality under varying field of views

The current best practice for hands-free selection using Virtual and Augmented Reality (VR/AR) head-mounted displays is to use head-gaze for aiming and dwell-time or clicking for triggering the selection. There is an observable trend for new VR and AR devices to come with integrated eye-tracking units to improve rendering, to provide means for attention analysis or for social interactions. Eye-gaze has been successfully used for human-computer interaction in other domains, primarily on desktop computers. In VR/AR systems, aiming via eye-gaze could be significantly faster and less exhausting than via head-gaze. To evaluate benefits of eye-gaze-based interaction methods in VR and AR, we compared aiming via head-gaze and aiming via eye-gaze. We show that eye-gaze outperforms head-gaze in terms of speed, task load, required head movement and user preference. We furthermore show that the advantages of eye-gaze further increase with larger FOV sizes.