Vision with the AN/PVS-5 Night Vision Goggles

This paper presents the results from a series of experiments in which visual performance using the ANPVS-5 night vision goggle was measured. Modulation transfer functions of the man-goggle system were determined and compared to results obtained with unaided viewing. It was found that the man- goggle system performance was superior to unaided visual performance at average target luminances equivalent to 5 and 25 moon illuminances. At a target luminance equivalent to a full moon illuminance, unaided visual performance was superior at higher spatial frequencies, while remaining poorer at the lower spatial frequencies. Using a modified Howard-Dolman apparatus, it was determined that the stereoscopic threshold was degraded with the man-goggle system. Field measurements of relative depth discrimination using all available visual cues showed that performance of the man-goggle system was statistically equivalent to unaided photopic visual performance at intermediate viewing distances, but was inferior to unaided viewing at distances of 500 feet or greater. While the night vision goggle reduces the ambient light level necessary for military rotary wing support, use of the goggle does not allow the operator to perform with photopic visual efficiency.