The ideas of handicapped derived "entitlements" is PC run amok.
"What Are The Other Requirements For A CDL?
Federal Motor Carrier Safety Regulations require drivers to be at least 21 years old and pass a physical examination once every 2 years. The main physical requirements include good hearing, 20/40 vision with or without glasses or corrective lenses, and a 70-degree field of vision in each eye. Drivers must not be colorblind."
http://www.testquestionsandanswers.com/cdl/california.html
Can the 9th Curcus overule that by fiat? Don't think so.