Ashley,
I think you are confusing a FIELD with a COURSE. There are certainly times when a student's disability may directly impact on their ability to succeed in a specific class (such as your example), but that is different from whether or not they can be successful in a field that may typically ask for that class as a part of the training. There MAY be occupations that are just impossible (like surgery for a blind student), but don't think in terms of matching abilities to the classroom. Think about the big picture.
Dr. Jane Jarrow