Eye movements in virtual environments

Author/Creator

Valeria Garro & Veronica Sundstedt

Quick Summary

Recent advancements in virtual reality (VR) with embedded eye-tracking offer new opportunities for research, but they also present unique challenges for data collection and analysis. This paper discusses best practices for validating 3D gaze-tracking in VR, highlighting a pilot study that indicates accuracy may vary with stimulus distance and cautions against relying solely on vergence for estimating gaze depth.

Abstract

Recent developments in commercial virtual reality (VR) hardware with embedded eye-tracking create tremendous opportunities for human subjects researchers. Accessible eye-tracking in VR opens new opportunities for highly controlled experimental setups in which participants can engage novel 3D digital environments. However, because VR embedded eye-tracking differs from the majority of historical eye-tracking research, in both providing for relatively unconstrained movement and stimulus presentation distances, there is a need for greater discussion around methods for implementation and validation of VR based eye-tracking tools.

The aim of this paper is to provide a practical introduction to the challenges of, and methods for, 3D gaze-tracking in VR with a focus on best practices for results validation and reporting. Specifically, first, we identify and define challenges and methods for collecting and analyzing 3D eye-tracking data in VR. Then, we introduce a validation pilot study with a focus on factors related to 3D gaze tracking.

The pilot study provides both a reference data point for a common commercial hardware/software platform (HTC Vive Pro Eye) and illustrates the proposed methods. One outcome of this study was the observation that accuracy and precision of collected data may depend on stimulus distance, which has consequences for studies where stimuli is presented on varying distances.

We also conclude that vergence is a potentially problematic basis for estimating gaze depth in VR and should be used with caution as the field move towards a more established method for 3D eye-tracking.

Eye movements in virtual environments

Eye-tracking is a powerful tool to study human behavior using the neuroergonomic approach. Lightweight and nonintrusive modern devices allow tracking the gaze in all kinds of real-life activities from cycling to piloting an aircraft. Virtual environments, on the other hand, allow full immersion of participants into well-controlled synthetic worlds where scientists can study human behavior in realistic situations at lower implementation cost and higher reproducibility compared to real life. The recent technological advancements made eye-tracking ubiquitous in virtual reality head-mounted displays. Whether it is used for foveated rendering or gaze-driven interaction, eye-tracking is one of the cornerstones for a successful virtual reality simulation. An increasing number of affordable VR HMD devices with integrated eye-tracking and, therefore, eye-tracking data, brings new challenges of understanding eye movements in virtual reality and designing efficient human-machine interactions. We invite submissions that incorporate eye movements in VR/AR/MxR for advancing the neuroergonomic approach from a broad spectrum of applications. Topics of interest include but are not limited to: • Eye movements during simulation or training in augmented/virtual/mixed reality • Visualization of eye and head movements from VR simulation • Methods for eye movements analysis for VR neuroergonomic studies • Gaze-based interaction in VR for neuroergonomic studies<...