Difference between impairment and disability
Impairment is any loss or abnormality of psychological, physiologic, or anatomic structure or function (e.g., impairment of vision). According to the World Health Organization (WHO) definition, disability results from impairment; it is any restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human. In governmental terms, disability is sometimes called a functional limitation. Another definition of disability is a disadvantage (resulting from an impairment or functional limitation) that limits or prevents the fulfillment of a role that is normal for an individual (depending on age, sex, and social and cultural factors). This definition corresponds to the WHO classification of handicap. Importantly, the presence of an impairment (e.g., visual impairment) does not necessarily have to lead to disability—individuals with visual impairment such as myopia can be assisted with corrective lenses to limit any disability associated with myopia.