BACKGROUND: Apache pilots needing refractive correction are issued modified HGU-4/P aviator spectacles. However, a recently published survey found field of view (FOV) dissatisfaction with the current spectacles when sighting in with a Helmet Display Unit (HDU). A current Air
Force flight frame was modified in-lab and the purpose of this study was to evaluate the FOV with the current Apache flight frame vs. the modified flight frame.METHODS: Recruited were 21 Apache pilots to assess FOV under three conditions: 1) wearing the current Apache frame; 2)
wearing the modified Apache frame; and 3) wearing no frame. The main outcome measure was total FOV of four quadrants tested: superior left (45°); superior right (135°); inferior right (225°); and inferior left (315°).RESULTS: No significant differences in FOV were
seen between the two frames tested while wearing the current Apache helmet (P = 0.33) and the new Apache helmet (P = 0.64). However, there were significant differences in FOV between the no frame condition and the two frame conditions tested with both helmets (P < 0.001).DISCUSSION:
No significant differences in FOV were seen between the two frames tested while wearing either Apache helmet. However, with both helmets there were significant differences in FOV between the no frame condition and the two frame conditions tested. This suggests that wearing no eyewear is still
optimal in integrating the HDU device. With advances in contact lens technology, future research can study the viability of the latest generation of multifocal contact lenses with Apache aviators.Walsh DV, Jurek GM, McLean WE, Statz JK, Allen RL, Riggs DW. Assessment of a prototype
Apache flight eyewear. Aerosp Med Hum Perform. 2016; 87(9):800–805.