Effect of combat eye protection on field of view among active-duty U.S. military personnel

Background: This study was conducted to determine if ballistic protective eyewear issued to U.S. military service members causes functional blind spots in the visual field. The study also investigated whether the use of corrective lenses with these devices contributes to defects in the visual field. Methods: Visual fields were measured using the Esterman Binocular Function test on the Humphrey Field Analyzer. Each subject performed the test with no devices and then repeated the test while wearing several combinations of ballistic eyewear (spectacles or goggles) and prescription correction. Mean differences in Esterman scores between each device and baseline were analyzed. Results: The spectacle devices did not show significant differences in mean Esterman scores from baseline. The goggle systems did show significant reductions in the peripheral field (P < 0.0001). The use of prescription correction with combat eye protection increased the number of missed points in the periphery by an average of 12.2% compared with ballistic devices alone (P < 0.0001). Conclusion: The use of ballistic protective goggles and prescription lens inserts with military combat eye protection causes a significant reduction in the peripheral field. Service members should be educated to replace eye movements with head movements when scanning the periphery.