Lack of International Uniformity in Assessing Color Vision Deficiency in Professional Pilots

Abstract

Color is an important characteristic of the aviation environment. Pilots must rapidly and accurately differentiate and identify colors. The medical standards published by the International Civil Aviation Organization (ICAO) require that pilots have "the ability to perceive readily those colors the perception of which is necessary for the safe performance of duties." The general wording of that color vision (CV) standard, coupled with the associated flexibility provisions, allows for different approaches to the assessment of color vision deficient (CVD) pilots. Data was gathered and analyzed regarding medical assessment practices applied by different countries to CVD pilots. Data was obtained from 78 countries, representing 78% of the population and 92% of the aviation activity of the world. That data indicates wide variation in the medical assessment of CVD pilots. Countries use different tools and procedures for the testing of pilots, and also apply different result criteria to those tests. At one extreme an applicant making one error upon Ishihara 24-plate pseudoisochromatic plate (PIP) testing is declined a class 1 medical assessment, while at another extreme an applicant failing every color vision test required by the regulatory authority may be issued a medical assessment allowing commercial and airline copilot privileges. The medical assessment of CVD applicants is not performed consistently across the world. Factors that favor uniformity have been inadequate to encourage countries toward consistent medical assessment outcomes. This data is not consistent with the highest practicable degree of uniformity in medical assessment outcomes, and encourages aeromedical tourism.