Adam, as you've probably read, the situation with JAA is as follows:
1. Ishihara Test, pass this and all is fine. Otherwise...
2. Choice of 4 further tests:
Holmes Wright Lantern
Beynes Lantern
Nagal Anomoloscope
Spectrolux Lantern
Pass any one of those, all is fine. Otherwise, you're
. There are no further step you can take, no relevant real life tests as there are in USA and Oz.
Before taking my JAA medical, I did the Ishihara test at an opticians. I got 2 plates wrong, which is a pass according to the manufacturers instructions. JAA abuse this test, administering it in breach of said instructions and will not accept ANY failures. If a doctor was to administer medical testing in that fashion they would be struck off.
I then visited Gatwick to do the lantern tests. They only have the Beynes and Holmes Wright. I failed the Beynes. I then took the Holmes Wright, but what the sneaky
don't tell you is that they adjust the shade of the colours. I didn't know this so despite thinking, "The last colour was green, this is lighter than that. It looks more green than white, but it's not the same colour as the previous green, so it MUST be white" - wrong, fail. Gatwick do not have the nagal or spectrolux. Helpful huh?
I visited City Uni and did a huge battery of tests as part of the CAA study (whose aims are to replace the current irrelevant testing regime with another similarly irrelevant testing regime). I was described as extremely mild, and they were very surprised I had not passed. I had a go at the Nagal whilst I was there and reached the JAA standard. This was not accepted by the CAA as it was not administered by an AME. Ho-hum.
In a fortnight I will fly to Zurich to take the Spectrolux lantern test (closest place!). I will duly report back as appropriate.
In the meantime as an IMC rated pilot I can fly in zero visibility, yet I'm apparently not capable of flying at night because I cannot pass a bunch of ancient and utterly irrelevant tests which are completely unrepresentative of the colour vision requirements in aviation today.