Effects of Bifocal and Progressive-Addition Corrective Lenses on Aviator Target-Detection Performance

摘要

The objective of this project was to determine if the type of presbyopiccorrection worn by aviators, conventional bifocal versus progressive-addition lenses (PALs), differentially affects aviator visual search performance. Experienced aviators with tactical fighter aircraft experience searched for high-contrast targets under simulated dawn/dust lighting conditions while wearing either a standard bifocal (ST-25) or PAL spectacle correction. Latency of locating high-contrast targets under these viewing conditions was affected differentially by the type of presbyopic correction used. Specifically, compared to a standard bifocal (ST-25), a PAL correction (Varilux Infinity) significantly lowered the time needed to locate static targets at a cockpit-instrument viewing distance (83 cm). Accuracy of target-location responses was not affected by the type of correction used. In addition, 7 months post experiment, 7 of the 12 participants (58%) indicated that they used their PAL correction exclusively when flying the T-39 Sabre Liner. Three subjects (25%) used their PAL correction intermittently (primarily at night) when flying, and two subjects preferred not to use the PALs. These results suggest that (a) relative to bifocals, speed of responding to static targets at intermediate viewing distances may be improved by wearing PALS; and (b) subjects were able to adapt to PAL lenses quickly in a laboratory setting, using them later in a functional aviation environment.