Evaluation of Functional Color Vision Requirements and Current Color Vision Screening Tests for Air Traffic Control Specialists

An experiment was conducted to evaluate the relation of type and degree of color vision deficiency and aeromedical color vision screening test scores to performance of color-dependent tasks of Air Traffic Control Specialists. The subjects included 37 normal tricromats of which 6 had mild color abnormalities. Those subjects with color vision deficiency included 18 simple anomalous trichromats, 22 extreme anomalous trichromats, and 31 dichromats; both protan and deutan types were included. Simulations of ATC color tasks concerned color coding in flight progress strips used a en route centers, and the Aviation Signal Light indicator light and aircraft lights as pertinent to ATC tower operations. Errors were rare among normals and those with mild color abnormalities in simulated normal operating conditions. Error frequency in the simulated ATC tasks was significantly higher among simple anomalous trichromats, and those with more severe deficiencies. The aeromedical screening tests were generally acceptable in terms of selecting individuals that did not make errors on the ATC tasks. These findings support the requirement that air traffic control personnel be normal trichromats. Recommendations for improvement of job-related color vision screening are discussed.