Vision test
Colour Vision Test
Colour perception assessment using Ishihara plates.
Duration
5 min
Category
Vision
Included in
9 medicals
What It Involves
Checks you can distinguish colours correctly, almost always using Ishihara plates. It matters for roles with colour-coded wiring, signals or warning systems - offshore, rail, aviation and diving all test for it. If Ishihara flags an issue, some sectors (maritime in particular) allow a more detailed CAD (Colour Assessment and Diagnosis) test as a fallback rather than an automatic fail.
What to Bring
Valid photo ID (passport or driving licence) (and 2 more items)
Frequently Asked Questions
Some sectors (notably maritime) allow a more detailed CAD test as a fallback rather than an automatic fail - ask your clinic if this applies to your medical.
No - it's a permanent condition, so there's nothing to prepare beyond attending in good, even lighting.
Health questionnaire
If your clinic requires a pre-visit health form, we'll email you their link. You complete it directly with the clinic — we never see or store your answers.