The International Classification of Functioning, Disability and Health (ICF), produced by the World Health Organization, distinguishes between body functions (physiological or psychological, e.g. vision) and body structures (anatomical parts, e.g. the eye and related structures). Impairment in bodily structure or function is defined as involving an anomaly, defect, loss or other significant deviation from certain generally accepted population standards, which may fluctuate over time. Activity is defined as the execution of a task or action. The ICF lists 9 broad domains of functioning which can be affected:
- Learning and applying knowledge
- General tasks and demands
- Domestic life
- Interpersonal interactions and relationships
- Major life areas Community, social and civic life
Main article: Medical model of disability
The medical model is presented as viewing disability as a problem of the person, directly caused by disease, trauma, or other health condition which therefore requires sustained medical care provided in the form of individual treatment by professionals. In the medical model, management of the disability is aimed at a “cure,” or the individual’s adjustment and behavioral change that would lead to an “almost-cure” or effective cure. In the medical model, medical care is viewed as the main issue, and at the political level, the principal response is that of modifying or reforming healthcare policy.
 The social model
Main article: Social model of disability
The social model of disability sees the issue of “disability” as a socially created problem and a matter of the full integration of individuals into society (see Inclusion (disability rights)). In this model, disability is not an attribute of an individual, but rather a complex collection of conditions, many of which are created by the social environment. Hence, the management of the problem requires social action and is the collective responsibility of society at large to make the environmental modifications necessary for the full participation of people with disabilities in all areas of social life. The issue is both cultural and ideological, requiring individual, community, and large-scale social change. From this perspective, equal access for someone with an impairment/disability is a human rights issue of major concern.
* The spectrum model refers to the range of visibility, audibility and sensibility under which mankind functions. The model asserts that disability does not necessarily mean reduced spectrum of operations.
* The moral model (Bowe, 1978) refers to the attitude that people are morally responsible for their own disability. For example, the disability may be seen as a result of bad actions of parents if congenital, or as a result of practising witchcraft if not. This attitude may also be viewed as a religious fundamentalist offshoot of the original animal roots of human beings when humans killed any baby that could not survive on its own in the wild. Echoes of this can be seen in the doctrine of karma in Indian religions.
* The expert/professional model has provided a traditional response to disability issues and can be seen as an offshoot of the medical model. Within its framework, professionals follow a process of identifying the impairment and its limitations (using the medical model), and taking the necessary action to improve the position of the disabled person. This has tended to produce a system in which an authoritarian, over-active service provider prescribes and acts for a passive client.
* The tragedy/charity model depicts disabled people as victims of circumstance who are deserving of pity. This, along with the medical model, are the models most used by non-disabled people to define and explain disability.
* The legitimacy model views disability as a value-based determination about which explanations for the atypical are legitimate for membership in the disability category. This viewpoint allows for multiple explanations and models to be considered as purposive and viable (DePoy & Gilson, 2004) (Elizabeth DePoy & Stephen Gilson).
* The social adapted model states although a person’s disability poses some limitations in an able-bodied society, oftentimes the surrounding society and environment are more limiting than the disability itself.
* The economic model defines disability by a person’s inability to participate in work. It also assesses the degree to which impairment affects an individual’s productivity and the economic consequences for the individual, employer and the state. Such consequences include loss of earnings for and payment for assistance by the individual; lower profit margins for the employer; and state welfare payments. This model is directly related to the charity/tragedy model.
* The empowering model allows for the person with a disability and his/her family to decide the course of their treatment and what services they wish to benefit from. This, in turn, turns the professional into a service provider whose role is to offer guidance and carry out the client’s decisions. In other words, this model “empowers” the individual to pursue his/her own goals.
* The market model of disability is minority rights and consumerist model of disability that recognizing people with disabilities and their Stakeholders as representing a large group of consumers, employees and voters. This model looks to personal identity to define disability and empowers people to chart their own destiny in everyday life, with a particular focus on economic empowerment. By this model, based on US Census data, there are 1.2 billion people in the world who consider themselves to have a disability. An additional two billion people are considered Stakeholders in disability (family/friends/employers), and when combined to the number of people without disabilities, represents 53% of the population. This model states that, due to the size of the demographic, companies and governments will serve the desires, pushed by demand as the message becomes prevalent in the cultural mainstream.