The Blind—Their Number and Characteristics

AN ACCURATE ENUMERATION of the blind in the United States is not available. I t is questionable whether such an enumeration could be made except through an elaborate case-finding method, since there is no precise and universally accepted definition of blindness, a lack which is undoubtedly in a measure responsible for the varied results of several attempts to enumerate the blind. Efforts have been made to obtain a consensus on the extent of visual deficiency that an individual must have in order to be classed as blind. I t has been agreed that the term cannot be restricted to persons who have no light perception whatsoever, but that it must include all whose vision is not sufficient for effective use. To define this larger group, various descriptive terms have been used, such as "economically," "vocationally," and "educationally" blind. The intent in broadening the concept of blindness is to include persons who may have enough vision to perceive light or motion but not to engage in normal everyday activities, such as attending school or following an occupation. In 1934 the American Medical Association, by resolution, adopted quantitative definitions of these terms as recommended by a committee appointed by the section on ophthalmology. To the States participating in the Federal-State program of aid to the blind under the provisions of the Social Security Act, the Social Security Board has suggested a definition of economic blindness which conforms essentially to that adopted by the American Medical Association: