Students with physical disabilities - blindness, deafness, etc
I would like to echo the other answers and enhance by focusing specifically on the breadth of ability challenges that may be faced by various students.  There are many different types of physical challenges that students may face, and even for a given challenge the answers may be different.  For example, did you know that most blind people can actually see, just so poorly that it cannot be effectively corrected, and that "blindness" actually covers a wide range of different conditions?

The key approach to any student with physical impairments that need accommodation is:


Do not assume that you should be handling it alone, or that you have the necessary knowledge to make an appropriate accommodation for that individual.
Ask the student.  They are the world's foremost expert on their condition and needs.  You'll generally do much better if you begin by just treating them like any other capable adult.
Get the university's experts involved, who will help you work out an appropriate plan tailored to an individual student.