Accessibility has improved in Athens since the Paralympic Games in 2004, but marble and stepped alleys are challenging for wheelchairs. People who have visual or hearing impairments are also rarely catered to, though at least there are the basic tactile sidewalk strips.
Careful planning before you go can make a world of difference.
Sage Traveling (www.sagetraveling.com/athens-accessible-travel) Detailed specs on Athens, based on a wheelchair rider's experience.
Matt Barrett's Greece Guides (www.greecetravel.com/handicapped) Links to local articles, resorts and tour groups catering to tourists with physical disabilities.
Download Lonely Planet's free Accessible Travel guides from http://lptravel.to/AccessibleTravel.