Colour Vision and the Aviation Medical
How colour vision is assessed for a medical certificate, the restriction that can result, and the operational tests that can remove it.
Colour vision is one of the standards checked at the aviation medical, because pilots must read signal lights, cockpit displays and airport lighting. A colour-vision deficiency is not automatically disqualifying, but it can lead to a restriction.
The screening
At the exam the AME administers an approved colour-vision screening test (such as a pseudoisochromatic plate test). If you pass, there is no colour-vision limitation on your certificate.
The restriction
If you do not pass the screening, the AME may issue the certificate with the limitation "Not valid for night flying or by color signal control." You can still fly, but not at night and not where you would rely on a light-gun signal from the tower.
Removing the restriction
The limitation is not permanent. You can take an operational colour-vision test administered by the FAA — historically involving signal-light and/or practical tests — and, if you pass, receive a Letter of Evidence (LOE) (the modern successor to the older *Statement of Demonstrated Ability*, or SODA) that removes the restriction from future certificates. Because you passed the operational demonstration, the LOE generally carries forward.
Plan ahead
If you know you have a colour-vision deficiency, arrange the operational test early — a night or signal-light restriction can otherwise limit training and hiring. For the broader picture, see medical certificate classes and BasicMed.
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*Reference and training only — not for navigation or as legal advice. Always consult the current 14 CFR, the AIM, your aircraft’s POH/AFM and a certificated flight instructor.*