Taming the Beast: Measuring Vision-Related Disability Using the International Classification of Functioning

This article reviews the way in which the complex phenomenon of vision-related disability is captured by an authoritative classification system: the International Classification of Functioning, Disability, and Health. Data from several major national surveys are used to illustrate how the classification system's codes referring to body function and structure, personal activities, social participation, and environmental factors relate to the surveys. Survey items specific to vision-related disability are considered in terms of codes in the International Classification of Functioning to show how the underlying conceptualization of survey questions maps to the classification system's domains. It is suggested that an understanding of the International Classification of Functioning can clarify the purposes and uses of survey questions dealing with vision-related disability. Efforts to develop standardized questions to improve comparability across surveys are encouraged.