Night Vision Goggles: Influence on Cognition, Gait, and Tactical Tasks.

Abstract

Background: Night vision goggles (NVG) grant warfighters a tactical advantage in low-light environments. However, NVG use can negatively affect visual acuity, depth perception, and color discrimination, which impacts warfighter safety and operational performance. Therefore, the purpose of this study was to examine the biomechanical effects in the walking phase of an obstacle clearance course and prefrontal cortex (PFC) regional oxygen saturation (rScO2) during embedded marksmanship and cognitive tasks performed with and without NVGs.

Methods: Twelve participants (21 [SD 1] years) completed an obstacle avoidance course with and without NVGs, which included pistol marksmanship assessments, cognitive assessments, and ground obstacles. Gait pattern, performance tasks, and PFC activity were recorded.

Results: Marksmanship performance decreased by 58.2% (P<.01), but cognitive performance was not impacted with NVG use (P=.676). Toe clearance increased by 32.2% (P<.01), toe velocity decreased by 20.5% (P<.01), and ankle dorsiflexion increased by 24.0% (P=.02) with NVG. Significant reductions in rScO2 during Marksmanship 2 (P<.01) and Cognitive Assessment Task 1 (P=.01) and 2 (P=.01) were observed.

Conclusion: Performance decrements with NVG use are hypothesized to be primarily due to altered vision perception and increased metabolic demand affecting marksmanship performance and gait patterns. NVG training may minimize the risk of musculoskeletal injuries and improve operational performance.