Measuring Visual Fatigue and Cognitive Load via Eye Tracking while Learning with Virtual Reality Head-Mounted Displays: A Review

ABSTRACT

Virtual Reality Head-Mounted Displays (HMDs) reached the consumer market and are used for learning purposes. Risks regarding visual fatigue and high cognitive load arise while using HMDs. These risks could impact learning efficiency. Visual fatigue and cognitive load can be measured with eye tracking, a technique that is progressively implemented in HMDs. Thus, we investigate how to assess visual fatigue and cognitive load via eye tracking. We conducted this review based on five research questions. We first described visual fatigue and possible cognitive overload while learning with HMDs. The review indicates that visual fatigue can be measured with blinks and cognitive load with pupil diameter based on thirty-seven included papers. Yet, distinguishing visual fatigue from cognitive load with such measures is challenging due to possible links between them. Despite measure interpretation issues, eye tracking is promising for live assessment. More researches are needed to make data interpretation more robust and document human factor risks when learning with HMDs.

Acknowledgments

This work was supported by Manzalab Group (Paris, France) and the French National Association of Research and Technology (ANRT) with the Grant CIFRE 2016-1571. The authors would like to thank Professor Ghislaine Azémard. The authors would like to thank reviewers for their feedback.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the French National Association of Research and Technology [CIFRE 2016-1571].

Notes on contributors

Alexis D. Souchet

Alexis D. Souchet works at the French National Centre for Scientific Research (CNRS) at the Heudiasyc laboratory as a Postdoctoral researcher. His researches focus on cognitive ergonomics, measuring visual fatigue, cognitive load, and stress while learning and working in Virtual Reality with physiological sensors.

Stéphanie Philippe

Stéphanie Philippe is R&D manager at Manzalab. She initially studied Biology and Therapeutics. She has then been involved in R&D management in various contexts and technological environments, from biotechnologies to cloud computing. She joined Manzalab and the fields of training and immersive technologies in 2016.

Domitile Lourdeaux

Domitile Lourdeaux is associate profressor at CNRS Heudiasyc UMR 7253 laboratory in University of Technology of Compiègne – Sorbonne University. Her research interests are the orchestration of virtual environments and autonomous virtual humans for training in critical/crises. She has been vice president of the French Association of Artificial Intelligence since 2020.

Laure Leroy

Laure Leroy is specialized in virtual reality. Her Ph.D. on stereoscopic interfaces at the School Mines Paristech, in the robotic center. She completed her postdoctoral studies on cognitive rehabilitation in virtual reality. She is now an associate professor at the Paris 8 University researching sensorimotor conflict reduction in virtual reality.