During a pilot medical examination, eyesight is thoroughly tested to ensure a candidate can safely operate an aircraft, as vision is critical for reading instruments, monitoring the environment, and interpreting signals. Examinations typically include distance vision (ability to see clearly at various ranges), near vision (for reading charts, instruments, and documents), color perception (to correctly identify signal lights, instrument indicators, and navigation aids), depth perception (to judge distances accurately for takeoffs, landings, and formation flying), and visual field testing (to ensure adequate peripheral awareness). These assessments are performed using standardized eye charts, color vision tests like Ishihara plates, stereopsis tests for depth perception, and perimetry for visual fields. Candidates can qualify with corrected vision using glasses or contact lenses, provided their corrected acuity meets regulatory standards. However, there are limits on refractive errors (for example, myopia or hyperopia thresholds) and restrictions for certain eye conditions; pilots with severe or progressive ocular diseases may be disqualified or require additional evaluation. Overall, these tests ensure that pilots maintain the visual acuity, color discrimination, depth perception, and field of vision necessary for safe cockpit operation and compliance with aviation safety standards.