The first time I taught a blind student, I was teaching C. I walked up to them to find they were clearly irritated, and said something like "Nothing works, I don't understand".

Looking at their computer, it appeared to be off. I said, delicately, that were they sure the computer was turned on. They laughed and turned their laptop's screen on, saying (as you say), they left it off to save battery life!

The problem turned out to be they were using textedit, which while a nice light (and highly accessible) editor, by default turns "s into “”. Unfortunately, Apple's text-to-speech "helpfully" just described all these as speech quotes. This made it impossible to understand, from the compiler error, why the code wasn't working. A quick head into settings and the student was off (they soon changed to textmate, also very accessible).