Effect Of Flashes Of Light On Night Visual Acuity
Report Number: WADC TR 52-10 Part 2
Author(s): Fry, Glenn A., Allen, Merrill J.
Corporate Author(s): Ohio State University Research Foundation
Laboratory: Aero Medical Laboratory
Date of Publication: 1953-01
Pages: 42
DoD Task:
PB Number: PB107339
Identifier: AD0013834
AD Number: 13834
Abstract:
Experiments were conducted to investigate a satisfactory method of predicting the course of constriction of the pupil of a dark-adapted eye when exposed to a flash of any duration or a series of flashes involving a complex distribution of brightness in the visual filed. Two aspects of the problem are considered. If the flash lasts longer than the latent period for pupil constriction, the pupil constriction will affect the amount of light reaching the retina during the latter portion of the flash. Also after the flash, the pupil does not return back to its normal size until after a considerable period of time. The investigation indicated that responses of a dark-adapted eye are proportional to the total amount of light involved (brightness x area x time). This conclusion holds roughly for the central region of the field of view up to 35 deg out from the primary line of sight and for flashes up to 0.2 sec. For flashes longer than 0.2 sec, the effect of varying duration was the same as that of varying brightness, and allowance must be made for the effect of the pupil constriction itself.
Provenance: Hunt Library, Embry-Riddle Aeronautical University
Author(s): Fry, Glenn A., Allen, Merrill J.
Corporate Author(s): Ohio State University Research Foundation
Laboratory: Aero Medical Laboratory
Date of Publication: 1953-01
Pages: 42
DoD Task:
PB Number: PB107339
Identifier: AD0013834
AD Number: 13834
Abstract:
Experiments were conducted to investigate a satisfactory method of predicting the course of constriction of the pupil of a dark-adapted eye when exposed to a flash of any duration or a series of flashes involving a complex distribution of brightness in the visual filed. Two aspects of the problem are considered. If the flash lasts longer than the latent period for pupil constriction, the pupil constriction will affect the amount of light reaching the retina during the latter portion of the flash. Also after the flash, the pupil does not return back to its normal size until after a considerable period of time. The investigation indicated that responses of a dark-adapted eye are proportional to the total amount of light involved (brightness x area x time). This conclusion holds roughly for the central region of the field of view up to 35 deg out from the primary line of sight and for flashes up to 0.2 sec. For flashes longer than 0.2 sec, the effect of varying duration was the same as that of varying brightness, and allowance must be made for the effect of the pupil constriction itself.
Provenance: Hunt Library, Embry-Riddle Aeronautical University