Color vision tests for aviation: comparison of the anomaloscope and three lantern types.

Abstract

Variability in pass/fail results can be attributed to many factors apart from loss of chromatic sensitivity. Some normal trichromats can fail both the Ishihara screening and the secondary tests. The approved secondary test varies between countries and the outcome of regulatory assessment depends on the color vision test used. Since the flight safety consequences of the current situation cannot be ignored, the development of a less variable technique for color vision assessment that is accepted internationally, allied with a better understanding of color vision requirements, is needed.