Dark focus measured in Navy jet tactical fighter pilots.

Visual accommodation was measured with the laser-Badal optometer in 98 U.S. Navy fighter pilots who were in a dark environment without visual stimuli. The average dark focus of the pilots was 0.25 diopters of myopia; 40% were either emmetropic or hyperopic in the dark. Only 4% had as much dark myopia as 50% of a sample of 220 college students. Although the jet fighter pilots, as a population, differed from college students in terms of dark focus, it remains to be determined whether the remarkable dark focus of the pilots was a function of training or selection. The dark focus measurements of the pilots were compared to their mean night carrier landing scores and their mean target detection slant range scores--the distance at which an adversary aircraft is first sighted during an air combat maneuver training engagement. Neither the night carrier landing scores nor the target detection slant range scores correlated significantly with dark focus measurements.