While diabetes is now the leading cause of death in America; and can cause all kinds of disabilities that would preclude being a locomotive engineer, it usually does not. In most cases, life and professions go on normally.

But should diabetes or anything else trigger a latent color blindness, it is problematic for a locomotive engineer (many other professions as well). I should know; diabetes has caused me serious enough disability that I had to leave my beloved job. I now work as a paralegal in a law office - never will be as interesting as the signal construction gang.

Moreover, not all CSX signals are color position - less than half are, and all the rest have a weird and inconsistent placement of colored lenses in signal heads. Anything to confuse the engineer - especially if he his just beginning to develop color blindness and hasn't recognized it yet.

But in the case I cited, the colorblindness was known, and then willfully covered up - a criminal act. Even though this engineer must have managed to read a thousand signals just fine, he screwed up just one (that we know of). The increased risk was there, and real, and it finally got him - and us too.

Nothing justifies putting the public at such risk - to a known disability. A diabetic must be alert to developing disabilities, and act accordingly. But most of the time, diabetes does not impair a locomotive engineer at all.