Vision requirements for Extended Reality displays in military aviation

Funding opportunity

Vision requirements for Extended Reality displays in military aviation

Anticipated timeline and budget

* First year funding in the amount of $95,000 has been re-allocated for Year 2.

Overview

Modern military aircraft use helmet-mounted Extended-Reality (XR) display technology to provide flight, aircraft, and tactical information to aircrew.  However, some users of these displays experience vision-related symptoms (e.g., visual fatigue, diplopia, and nausea), that could negatively affect performance and operational readiness. Empirical research is required to determine the individual differences in vision that contribute to performance and compatibility with XR displays and identify clinical tools and standards that can be employed to increase the efficiency of aircrew selection for roles that employ these displays.

Defence Research and Development Canada (DRDC) is investigating this topic in support of the Canadian Forces Health Services (CFHS) and the Royal Canadian Air Force (RCAF). As part of this effort, DRDC is sponsoring a funding opportunity for research to:

• Empirically determine the links between individual differences in binocular vision and performance/compatibility with XR displays in military aviation
• Identify clinical tools that can be used to select individuals in this context
• Develop clinical guidelines to maximize the pool of individuals that can safely and effectively use these systems.

Background

CFHS has a requirement to evaluate the vision health of members of the RCAF to ensure they meet military safety standards, which require periodic review as new aircraft, avionics, and aircrew tasks are introduced. Modern military aviation is increasingly utilizing helmet-mounted heads-up display (HUD) to alleviate cognitive load in pilots who need to monitor and control multiple aircraft functions. These HUD elements may be shown with transparency so that the pilot can see-through the display and observe the cockpit and through the canopy, or in other instances the HUD might be overlaid on synthetic scene imagery that is presented in the head-mounted display. These head-mounted aviation displays may be considered 'Augmented Reality' (AR) displays, falling into the category of Extended Reality (XR) in the consumer market.

Applications of XR displays in the civilian domain have revealed significant usability issues. One well-documented issue in civilian applications is “cybersickness”, where the user can experience a cluster of negative symptoms centered around nausea and motion sickness. This issue has been associated with immersive simulations including flight/vehicle simulators and Virtual Reality (VR) displays but is also reported to affect other display types within the XR spectrum, such as Augmented Reality (AR). Cybersickness also has a visual component, including eye strain and visual fatigue. Accordingly, aspects of cybersickness are expected to be relevant in the context of aeromedical vision assessment.

Military aviation represents a very different context for XR displays compared to the civilian domain, due to differences in the user population, tasks, and environment. Military pilots perform aerial maneuvers that impose extreme forces on the body, and that can cause air sickness in inexperienced individuals. These maneuvers might also be conducted under hypobaric and potentially hypoxic atmospheric conditions. While cybersickness might be expected under these conditions, anecdotal reports point to visual issues such as eye strain, blurred vision, and diplopia as the primary negative symptoms. These symptoms are suspected to relate to binocular vision; for example, users may have difficulty fusing the XR displayed images from each eye, and they might experience strain due to vergence-accommodation mismatch or frequent shifts in focal plane. While some of the usability issues with XR displays might be resolved through technological improvement, from a personnel selection standpoint it is critical to know whether there are individual differences in binocular vision that influence whether an individual will be able use these devices to their full potential, and for an extended period (e.g., hours), during military operations.

Scope and research objectives

• Design and conduct an empirical investigation into the prospective binocular vision requirements for the use of XR displays in military aviation.
• Incorporate a simulated military aviation task that constitutes an ecologically valid employment of the XR display capability. In particular, the task simulation should include a head- or helmet-mounted augmented reality display that binocularly presents overlay elements such as airspeed, aircraft information, and tactical information while the user views the cockpit instruments and scenery outside of the aircraft.
• Employ this task simulation in individual-differences research to link binocular vision variables with flight task performance and participant subjective feedback. This work will inform vision standards for personnel selection, targeting the general Canadian public who may seek military service.
• The key guiding questions for this work are:
  1. What aspects of binocular vision are critical for, or enable, performance and usability with XR displays in military aviation?
  2. What clinical measures or tests can quantify these vision functions accurately, and reliably, and thus be used aircrew medical evaluation?
  3. Are there sensible boundaries or cut-offs on these measures that would maximize the inclusion of individuals that can safely and effectively use of XR displays in military aviation?

Desired outputs

• Study Design and Ethics Protocol: The Award Recipient will develop the study design in collaboration with the DRDC Sponsor to ensure alignment with program objectives. The Award Recipient will also prepare and submit the appropriate ethics protocol(s) for review and approval, covering the study’s data collection activities.
• Progress Reviews: The Award Recipient will provide regular updates to the DRDC Sponsor to share progress towards key milestones. These updates may be in the form of reports, meetings, or other agreed-upon methods of communication.
• Final Report: Upon completion of the project, the Award Recipient will submit a final report detailing the study’s methodology, findings, and conclusions. This report will aim to link clinical measures of vision with users' task performance and experiences in using XR displays and provide insights or guidelines on how these measures could improve the safe and effective use of XR displays in aviation settings.
• Data Sharing: The Award Recipient will make anonymized data sets resulting from the study available to the DRDC Sponsor, in line with ethical considerations and data-sharing agreements.
• Publication of Findings: The Award Recipient is encouraged to collaborate with the DRDC Sponsor to publish the study results in peer-reviewed journals or other relevant publications, contributing to the broader scientific community and advancing knowledge in the field.

Applicant qualifications and requirements for selection

• Applicant team will be led by a senior researcher with a PhD in a relevant field (Perceptual Psychology, Optometry and Vision Science, etc.).
• Applicant team includes substantial expertise on visual human factors of XR displays, demonstrated in peer-reviewed scientific publications.
• Applicant team has experience conducting research on vision requirements for military aviation, demonstrated in peer-reviewed scientific publications.
• Applicant team has expertise on individual differences in visual perception and clinical measurement of vision, with an emphasis on binocular vision (e.g., stereopsis, fusion, ocular alignment).

Application deadline

Please download and submit the Research Funding Application form.

Enquiries

Questions about this funding opportunity can be sent to the VAC Research office.

References

Kennedy, R. S., Lane, N. E., Berbaum, K. S., Lilienthal, M. G. (1993). Simulator sickness questionnaire: An enhanced method for quantifying simulator sickness. The International Journal of Aviation Psychology, 3(3), 203-220.

Saredakis, D., & Szpak, A., Birckhead, B., Keage, H. A. D., Rizzo, A., & Loetscher, T. (2020) Human factors associated with virtual reality sickness in head-mounted displays: A systematic review of meta-analysis. Frontiers in Human Neuroscience, 14 (96), 1-17, doi: https://doi.org/10.3389/fnhum.2020.00096

Stanney, K., Lawson, B. D., Rokers, B., Dennison, M., Fidopiastis, C., Stoffregen, T., Weech, S., & Fulvio, J. M. (2020). Identifying causes of and solutions for cybersickness in immersive technology: Reformulation of a research and development agenda. International Journal of Human-Computer Interaction, 36 (19), 1783-1803, doi: 10.1080/10447318.2020.1828535