vilberg.com
They also complained he did not know how to teach because he is blind.

Students gave bad reviews when a prof called on them “even when they didn’t raise their hands.” “They also complained he did not know how to teach because he is blind.” He was denied tenure based on the teaching evaluations.

Is it the students or the prof (or the institution) with the problem?

http://www.insidehighered.com/news/2011/10/31/after-student-complaints-utah-professor-denied-job