My son is color blind. It kept him from being an airplane mechanic in the Air Force. If you can't tell those yellow wires from the green wires, no one wants to fly the planes you rewired! I didn't know until he was about 6 and went in for his first eye exam.
I had to tell one teacher several times that he couldn't color code maps. I got really steamed when she took off points on a test due to not using the correct color. I think she fixed that grade after I talked to her!
The genetics of color blindness is fascinating. My mother's father was color blind, it kept him from being promoted to engineer on the train. Wow, I just roughly figured that had to have been at least 90 years ago! My mom would have been 94 this year, and he lost that opportunity somewhere around that time.
