The Ishihara test was intended as a screening test and it's reasonably good for that purpose. The more advanced forms of colour-vision testing involve more equipment and take a good amount of training to administer fairly, so there's a reason most AMEs will use the Ishihara plates as a first resort. But it is possible to pass one test, but fail another so if you haven't yet done a lantern test I suggest you have a shot at one and see how you do.
Last edited by abgd; 15th January 2012 at 05:58.