It is a bad few minutes. You are sitting in the AME’s office, the exam has gone fine, and then you get to the color plates. You miss some. The examiner makes a note, and suddenly the medical certificate you assumed was a formality is a question mark.
I see pilots in this exact situation, and the first thing I tell them is that missing plates is not a verdict. It is one screening result from one kind of test, and the FAA has other tests it accepts.
Why Plates Are Not the Whole Picture
Ishihara plates and similar pseudoisochromatic plate books are screening tools. They are quick, they are inexpensive, and they are good at flagging that something may be off. What they are not good at is telling you how much colour discrimination you actually have.
Plates give a pass or fail against a threshold. A person with a very mild colour vision deficiency and a person with a significant one can both miss plates, and the plate book cannot separate them. For a lot of everyday purposes that does not matter. For aviation medical certification, where the question is whether you can do a specific set of tasks, it matters a great deal.
That is the gap computerized colour vision testing was built to fill.
What the FAA Accepts Instead
Effective 1 January 2025, the FAA’s guidance for Aviation Medical Examiners lists a specific set of computer-based colour vision tests it accepts for pilot screening. The Rabin Cone Test is one of them, alongside the Colour Assessment and Diagnosis (CAD) test and the Waggoner computerized tests.
Two details matter and catch people out:
Testing must be done in person. Virtual, downloaded and printed versions are not accepted. If you find a version of one of these tests online, it will not count.
Tests not on the list are not acceptable. The FAA is specific about which instruments qualify, so “a colour vision test” is not the same thing as an accepted one.
You can read the current requirements directly in the FAA Guide for Aviation Medical Examiners, and I would encourage you to, rather than relying on forum posts.
What the Rabin Cone Test Actually Measures
The Rabin Cone Contrast Test does not ask you to find a number in a field of dots. It presents coloured letters at decreasing contrast and measures how faint a letter you can still identify, separately for red, green and blue, and separately for each eye.
The result is a score per colour channel per eye, not a pass or fail stamp. The FAA standard is 55 or higher in each colour, in each eye, and each individual score has to meet it. A strong red score does not make up for a weak green one.
That per-channel detail is the reason the test exists. It tells your AME something specific rather than something binary.
What Happens If Your AME Does Not Have One
This is the situation most pilots I see are actually in. Their examiner does not have an accepted computerized test in the office.
FAA guidance addresses this directly: testing can be completed at a separate clinic, with the patient bringing the printed results back to the AME. That is a normal, expected pathway, not a workaround. It is also the reason a practice like ours ends up seeing pilots from well outside our own towns.
At Everyday Eye Care the test is $150, takes about ten minutes, and you leave with the official computer-generated report the same visit. Full details are on our Rabin Cone Contrast Testing page.
Be Straight With Yourself About the Outcome
I am not going to tell you that computerized testing turns every failed plate result into a pass. It does not. What it does is measure your colour vision properly instead of screening it roughly, and for a meaningful number of pilots the detailed result is better than the plate result suggested.
For others, it confirms a real deficiency. That is worth knowing too, because it lets you and your AME have an accurate conversation about what comes next instead of guessing.
What I will not do is tell you in advance how you will score. Nobody honest can.
A Few Practical Points
Bring photo ID. Testing done for aviation, employment or licensing purposes needs identification.
Wear your current correction. Colour scores are only valid if the letters are sharp for you at the testing distance. An out-of-date prescription can affect the result, which is one of several reasons I suggest pairing the test with a comprehensive eye examination when it makes sense.
Do not practise on simulated versions. Beyond the fact that online versions are not accepted, familiarising yourself with test material undermines the point of testing.
The screening is one-time. Under current guidance, a pilot who has previously passed an accepted colour vision test does not need to repeat the computer-based screening. If that applies to you, say so before you book anything.
Where the Decision Actually Sits
One thing I want to be clear about, because it comes up every time: I perform the test and give you the report. I do not issue medical certificates and I cannot overrule an examiner.
Final aeromedical certification decisions belong to the FAA and your Aviation Medical Examiner. My role is to hand you an accurate, properly conducted measurement so that decision is made on good information.
If You Are Sitting on a Deferred Medical
Call the office nearest you and say you need FAA colour vision testing. We schedule this by phone rather than online so we can reserve the right appointment slot and confirm you are booking the right thing.
Everyday Eye Care performs Rabin Cone Contrast Testing at our Pasco and Sunnyside, Washington offices and our Hermiston, Oregon office. Pilots travel to us from across both states, so if you cannot find the test near you, call before you make the trip and we will make sure the visit is worth it.