VALIDITY OF THE HOLMES-WRIGHT LANTERN AS A COLOR-VISION TEST FOR THE RAIL INDUSTRY

A simulated field test was designed to determine whether the Holmes-Wr ight A lantern (HWA) is a valid color vision test for the rail industr y. The simulation replicated viewing rail signal lights at 0.8 km dist ance under daylight conditions. Using the worst-normal as the maximum number of allowable errors on the simulation, 94% of the color-defecti ves failed both tests on the first trial and 92% failed at the second session. The HWA had a higher false negative rate than a false alarm r ate. The majority of individuals who had discrepancies on the two test s were mild deutans. Results from the Ishihara test were marginally be tter at predicting performance on the simulation. (C) 1998 Elsevier Sc ience Ltd. All rights reserved.