Colour Vision Examinations - How do you do it?

[Phil Smith]

Hi,

Could anyone please tell me what the current standards and testing methods are to examine and determine the degree of colour vision deficiency.

I am particularly interested in the methods used for these following countries: USA, Australia, New Zealand and Canada.

Your help in this matter could go a long way for UK and European pilots.

Thank you.

[Max Gross]

In the US the first test administered is usually ishihara, if you fail this then there are a large number of alternative accepted tests approx 15 in total a pass in any one of these is good enough for life. You will be given a letter from the FAA saying that you meet the standard so that you can show it to subsequent medical examiners who may not have the test that you passed.

If you fail all the accepted tests the there is one final test that you can do, it is the signal light test. What happens is that you get your medical from the FAA with the restriction prohibiting night flight and flight by color signal control, then you make an appointment with the local FAA office and they take you out onto an airfield with an FAA control tower. The control tower flashes light signals at you and you have to name them to the inspector standing next to you. The test is done at 1000ft distance and repeated at 1500ft, the order of the colors is random. If you pass you get the same letter as above, good for life.

The signal light test can be passed by most people. It has been used by the FAA since the FAA's inception in 1958 and previously used by the FAA's predecessor since flying started to be regulated. Thousands of pilots have been passed by this test alone and their historical safety record is 100% (never has a pilot who can pass this test been involved in an accident or incident where he confused safety critical colors)

This signal light test is also used in Australia.

[Phil Smith]

Max,

Would a colour defective pilot (having passed the signal gun test in the US) be allowed to exercise his night rating in the UK / Europe?

I think the answer is no, but can you confirm?

[redsnail]

I can't give a definitive answer on this. What a few people have done in Australia is proven to CASA that they can operate safely with their vision defects.
A guy I know who is a "deutan" had a FAA IR and proved to CASA that he can operate safely because he had "x" number of hours doing just that.
Another friend who passed her class 1 vision standard years ago for CASA developed problems in her vision. She had been operating wide body jets. Her vision was corrected back to the standard with glasses and she was allowed to fly because she could prove that she had operated aircraft safely. She also managed to get that waiver from the CAA. On paper she shouldn't have because her eyes are now out of JAR tolerance.

In a nutshell, you have to be able to prove to the authority that your eyes aren't a problem in safely operating an aircraft. There's no guarantee that they will go in your favour but it has to be better than nothing.
The colour blind pilots in Australia have Dr Arthur Pape to thank. His tireless efforts changed the rules there.

[Max Gross]

Phil Yes and no is the best answer, If you fly N reg aircraft then no problem but the issue with JAR medicals is unlikley to change in the near future.

The really ridiculous part is that lots of US pilots are flying for US airlines all over JAA airspace with this and many other types of waivers yet the local boys are prohibited.

The US pilots have as good a medical safety record as the Europeans.

What is very likley is that this will eventually be put right by European legislation on disabilities.

Essentially very clear evidence exists to show that colour defectives are as safe as their colour normal counterparts yet are being discriminated against on the grounds that they pose an unacceptable risk.

[interestedparty]

The Ishihara test is generally used to determine gross errors such as red/green colour blindness. Some might question why red & green signals are used on roads almost universally, and indeed on British railways. Interestingly French railways use cyan/magenta signals.
I am unaware how precise colour vision needs to be for commercial pilot, but for those who require "perfect" colour vision a chromaticity test is normally used. This involves arranging a large number of coloured pegs or balls in ranks corresponding to their hue and saturation. Needless to say it is very time consuming, and probably unnecessarily precise for most occupations.
John Burgess