The Americans with Disabilities Act (ADA), prohibits private business and government agencies with 15 or more employees from discriminating against a qualified handicapped person in all manner of the employment process from hiring to performance to termination.
Employers are allowed to ask prospective employees about their ability to perform a specific job function but they're not allowed to ask them about their disabilities per se.
Reasonable accommodation for disabled job applicants refers to not asking embarrassing questions during the interview and also to make reasonable physical accommodations.
Regardless of the particular disability, be it mobility limitation, sight or hearing impairment or a chronic condition like multiple sclerosis, the company is supposed to provide assistance in all these matters.
This might be to provide a sign language reader, provide a reading enlarger machine for the visually impaired or build a ramp to enable a wheelchair user to enter the building.