The Medical Examiner must follow the standards found in 49 CFR 391.41. In the case of vision, hearing, epilepsy and diabetes requiring any use of insulin, the FMCSRs standards are absolute and allow no discretion by the Medical Examiner.
FMCSA also provides medical advisory criteria and medical guidelines to assist the Medical Examiner determine if a person is physically qualified to operate a commercial bus or truck. The Medical Examiner may or may not choose to use these guidelines. These guidelines are based on expert review and considered practice standards. The examiner should document the reason(s) for not following the guidelines.