The photic sneeze reflex as a risk factor to combat pilots.

The tendency to sneeze upon exposure to bright light is autosomal dominant and affects 18-35% of the population. This uncontrolled sneezing may represent a danger to pilots during flight. Testing was conducted using Ditric narrow band (+/- 10 nm) interference filters. Wavelengths at 430, 532, and 560 nm were tested with a GE 500-W photoflood BCA #1 bulb at constant intensity. Subsequent testing of military and civilian aviation goggles and sunglasses was conducted using a Digikrom 240 monochromator. Repeated testing with interference filters in a clinical setting showed no effect on sneezing in a susceptible subject. The photic sneeze reflex does not appear to be mediated by specific wavelengths of light, but rather by the change in light intensity. This could trigger an unexpected sneezing episode during critical periods of flight. This is an unrecognized and previously unreported danger to fixed-wing and rotary aircraft pilots.