What is a common method for color vision screening in aviation?

• A. Snellen eye chart
• B. Visual field perimetry
• C. MRI
• D. Ishihara color plates test

Answer: (D)

Color vision screening in aviation focuses on quickly identifying red-green color deficiencies, since these are the most common and can affect recognizing cockpit and aviation signals that use color coding. The Ishihara color plates test presents a series of plates with numbers or patterns formed by colors that color-normal vision sees as one thing, while red-green deficiencies see a different figure or cannot identify it at all. This makes it a quick, standardized screening tool that fits nicely into medical examinations for pilots, allowing a rapid pass/fail assessment and guiding whether more detailed testing is needed.

In contrast, a Snellen eye chart checks visual acuity (sharpness of vision), not color discrimination; visual field perimetry assesses the extent of the field of view; and MRI is unrelated to testing color perception.