Originally Posted by
LivingInMEM
From what I learned from an opthomologist, this is not true. First, color blind is what the general public calls it and color deficient is what the doctors call it. Second, while color deficiencies are present from birth to death in some people, there are ways (such as trauma or disease) for people with otherwise normal vision to acquire color deficiencies.
There are also several degrees of color deficiencies involving varying degrees (mild, moderate, severe) and colors. The number plates are just a screening test, and as many as 10% of the people who pass the number plates will fail more in-depth color deficiency tests. Just ask the USAF acquisitions who passed their initial flight physicals (including the number plate) only to be eliminated at the next stage for color deficiencies that were detected by more detailed tests at Brooks AFB. Everyone who failed the initial exam were eliminated at that stage, those that passed went on to Brooks for the more detailed screenings.
There are also cases to prove the contrary... People failing the PIP's (Ishihara Plates) and strangely doing better than 'color normals' on anomaloscope test or other more accurate and in depth tests... The problem with the color plates is that they are calibrated to the average normal... Some normals are better at telling reds from blues than other normals, same with other normals being better able to tell reds from greens, etc... you get the point.
I work right down the office with a guy who is Achromatic. That is he suffers "Achromatopsia". Extremely rare, he was even on TV once about it... 0.0033% of the population has this. He can only see in black and white... and shades of gray... period.
You know what's funny? He can do better than me on some of the Ishihara plates.
A real world test should always be an option for people. Anything else is just based on bad science and unfair.
See:
http://www.vfcev.de/content/eng-arti...es/001/001.htm