ABSTRACT
The population of persons who are disabled constitutes one fifth of the population in the
United States (McNeil, 1993), and it has been estimated that at least 40% of this group
has disabilities that cannot be seen, or are “invisible” (Asch, 1984). Matthews (1994)
defined invisible disability as “one that is hidden so as not to be immediately noticed by
an observer except under unusual circumstances or by disclosure from the disabled
person or other outside source” (p. 7). The category of invisible disabilities includes both
physical and mental conditions. Physical conditions include those resulting from chronic
illnesses, such as heart disease, or neuromuscular diseases, such as epilepsy; mental
conditions include various neuroses and learning disabilities as well as cognitive
processing problems like dementia and mental retardation.
