Not to my knowledge. At least nothing specifically designed for the physically handicapped.
However, I believe the earpiece in the standard handset is hearing aid compatible.
Also someone who is blind should have no trouble using any of the Mitel instruments as all of their legacy instruments have standard DTMF keypads (standard layout geometry). Multiline key appearances (i.e., an attendant's console or receptionist's or admin assistant's position) might pose something of a challenge, however.
What are you looking for?