It could be something as simple as requesting a quiet workspace. Or it could be something as significant as asking to have a new desk that accommodates your wheelchair. If it is reasonable and does not constitute an "undue hardship" on the part of your employer, your disability request must be provided.
What is considered a disability?
The Americans with Disabilities (ADA) act was signed into law in July 1990. The act created a requirement that your employer make changes to your work environment that allow you to work. According to the U.S. Office of Personnel Management, the following is required for any employer with a disabled employed: