The Visual Effects of Exposure to Electroluminescent Instrument Lighting

Abstract

This report describes two experiments with electroluminescent aircraft instrument lighting. In the first experiment, white electroluminescent, green electroluminescent, and red incandescent lighting were compared for their effects on dark-adapted, scotopic absolute and acuity thresholds, using a simulated T-38 instrument panel for light exposure. In the second experiment, white, green, and yellow electroluminescent and red incandescent light were compared in terms of legibility of a transilluminated letter-acuity chart. Exposure to red incandescent lighting at 0.05 ft.-l. produced the lowest absolute and acuity thresholds, with white and green electroluminescent producing higher thresholds in that order. Although threshold differences between lighting colors were statistically significant, the absolute differences in visual sensitivity were small for practical purposes. Luminances required for equal legibility of transilluminated letters of various sizes were about the same for red incandescent, and white, green, and yellow electroluminescent lamps. Electroluminescent lighting of aircraft instruments is discussed.