While accommodating people with invisible disabilities is mandated by law, what specifically constitutes a disability is opaque, and what constitutes accommodation is just as vague. The Americans With Disabilities Act (A.D.A.), which marks its 30th anniversary this month, requires employers, businesses, public facilities, transportation and telecommunications to make accommodations for a disabled person whose physical or mental impairment interferes with one or more major life activities. An autistic person, or a person with a mental illness, will often be disdained or even assailed for peculiar or antisocial behavior. A person who walks with a limp but uses no physical support may be jostled on the street like anyone else. to addictive disorder to lupus - that aren’t necessarily helped by a designated parking spot. But an untold number of people have disabilities - from A.D.H.D. The word “disability” evokes images of ramps, lower-positioned urinals, grab bars and other allowances in our architectural landscape. Such social insensitivity is endemic to the lives of people with permanent but invisible disabilities that affect their daily functioning, who are likewise deprived of outer symbols to signal their condition. I neither anticipate nor receive public compassion. Because my intermittent disability is invisible, in the thick of it I have often felt compelled to make myself invisible. When my depression mushrooms, I shun visibility I walk so close to buildings that my shoulder becomes dirty. These conditions are well-controlled most of the time, but when I have a significant dip, no one makes anything easier for me unless I explain it all to them - an unpleasant effort at the best of times and beyond my ken at the worst.