Definition of Disability, Handicap & Impairment


Owing to improved health services, disabled people are living longer, their presence in society is becoming more visible and their numbers are growing. Defining disability is difficult because there are dozens of definitions – each with a purpose to it. These range from the very narrow to the very broad, from the medical to the social, from the cultural to the local, from the one intended to integrate them in society to the one for exclusion and segregation. People are labelled as disabled or handicapped because they look different from the rest of the society on account of their appearance, behaviour or capacity to learn.
Impairment is any loss or abnormality of psychological, physiological or anatomical structure or function.
A disability is any restriction or lack (resulting from an impairment) of ability to perform an activity in the manner or within the range considered normal for a human being.
A handicap is a disadvantage for a given individual, resulting from an impairment or disability that limits or prevents the fulfillment of a role that is normal (depending on age, sex and social and cultural factors) for that individual.
A disabled person is an individual whose prospects of securing, retaining and advancing in suitable employment are substantially reduced as a result of a duly recognized physical or mental impairment.
Hearing handicap
means deafness with hearing impairment of 90 decibels and above in the better ear or total loss of hearing in both ears.
Locomotor disability
means a person’s inability to execute distinctive activities associated with moving, both himself and objects, from place to place, and such inability resulting from affliction of either bones, joints, muscles or nerves.
Mental retardation
means a condition of arrested or incomplete development of mind of a person which is specially characterized by sub-normality of intelligence.
Visually handicapped 
means a person who suffers from any of the following conditions, namely :

  1. total absence of sight; or
  2. visual acuity not exceeding 6/60 or 20/200 (Snellen) in the better eye with the correcting lenses; or
  3. limitation of the field of vision subtending an angle of degree 20 or worse.
According to Helander the simplest and maybe the initial definition of a disabled person appears to be the following:
“A person who in his/her society is regarded as disabled, because of a difference in appearances and/or behaviour.”
In most instances, a disabled person has functional limitations and/or activity restrictions. A functional limitation disability may be defined as – specific reductions in bodily functions that are described at the level of the person’.
‘Activity restriction’ disability may be defined as ‘specific reductions in daily activities that are described at the level of the person’.
Helander’s definition – A disabled person is the one who in his or her society is regarded or officially recognized as such, because of a difference in appearance and/or behaviour, in combination with a functional limitation or an activity restriction.

In the definition given by the Planning Commission of India, a disabled person means a person who is

  1. blind
  2. deaf
  3. having orthopaedic disability; or
  4. having neurological disorder
  5. mentally retarded
The definition includes ‘any person who is unable to ensure himself/herself, wholly or partly, the necessities of a normal individual or social life including work, as a result of deficiency in his/her physical or mental capability’.
A person shall be deemed to be blind if he/she suffers from either
of the following conditions –

  1. total absence of sight;
  2. limitation of the field of vision subtending an angle of 20 degrees or worse.

A person shall be deemed to be deaf if he/she has lost 60 decibels or more in the better ear in the conversational range of frequencies. 

Orthopaedic or neurological disorder
A person shall be deemed to be orthopaedically or neurologically disabled  if he/she is having disability of bones, joints or muscles leading to substantial restriction of the movement of the limbs or if he has any form of Cerebral palsy.
Mental retardation
Mental retardation refers to sub-average general intellectual functioning, which originates during the development period.
The Ministry, now known as Ministry of Social Justice and Empowerment, issued orders prescribing a standard set of definitions along with standard tests for the purposes of certification of disability. These definitions (whose suitability in the light of new legal safeguards must be carefully examined) were adopted and used.
Four major categories of disability the definitions are as follows : 

Visually handicapped

The blind are those who suffer from either of the following conditions :

  1.  Total absence of sight;
  2.  Visual acuity not exceeding 6/60 or 20/200 (Snellen) in the better eye with correcting lenses.
  3. Limitation of the field of vision surrounding an angle of degree 20 or worse.
The locomotor handicapped are those who have restriction in the activity of arms, limbs or other parts of the body on account of damage to the  bones, muscles or nerves. Persons suffering from more than 40 per cent disability would be entitled to facilities/concessions provided by Central/State governments.
Hearing handicapped
The deaf are those in whom the sense of hearing is non-functional for ordinary purposes in life. They do not hear/understand sound at all even with amplified speech. The cases included in this category will be those having hearing loss of more than 90 decibels in the better ear (profound impairment) or total loss of hearing in both ears.
Mental retardation
Mental retardation means sub average general intellectual functioning associated with mal-adaptive behaviour, occurring in the developmental period. Mental retardation is divisible into the following four categories

  1. Mild retardation IQ – 50 – 9
  2. Moderate retardation IQ – 35 – 49
  3. Severe retardation IQ – 20 – 34
  4. Profound retardation IQ under 20
Definition according to Persons with Disabilities (Equal Opportunities, Protection Of Rights And Full Participation) Act, 1995

Disability means – Blindness, Low vision, Leprosy cured, Hearing impairment, Mental retardation, Mental illness.

Blindness‘ refers to a condition where a person suffers from any of the
following conditions, namely –

  •  1. Total absence of sight; or
  •  2. Visual acuity not exceeding 6/60 or 20/200 (Snellen) in the better eye with correcting lenses; or
  • 3. Limitation of the field of vision subtending an angle of 20 degrees or worse.
‘Cerebral Palsy’ means a group of non-progressive conditions of a person characterized by abnormal motor control posture resulting from brain insult or injuries occurring in the pre-natal, peri-natal or infant period of development.
‘Hearing impairment’ means loss of sixty decibels or more in the better ear in the conversational range of frequencies.
‘Leprosy cured person’ means any person who has been cured of leprosy but is suffering from –

  1. loss of sensation in hands or feet as well as loss of sensation and paresis in the eye and eye-lid but with no manifest deformity;
  2. manifest deformity and paresis but having sufficient mobility in their hands and feet to enable them to engage in normal economic activity ;
  3. extreme physical deformity as well as advanced age which prevent him from undertaking any gainful occupation, and the expression leprosy cured shall be construed accordingly.
‘Locomotor disability’ means disability of the bones, joints or muscles leading to substantial restriction of the movement of the limbs or any form of cerebral palsy.
‘Mental illness’ means any mental disorder other than mental retardation.
‘Mental retardation’ means a condition of arrested or incomplete development of the mind of a person, which is specially characterized by sub normality of intelligence.
‘Person with disability’ means a person suffering from not less than forty percent of any disability as certified by a medical authority.
‘Person with low vision’ means a person with impairment of visual functioning even after treatment or standard refractive correction but who uses or is potentially capable of using vision for the planning or execution of appropriate assisitive device.


The term ‘disability‘ summarizes a great number of different functional limitations occurring in any population in any country of the world. People may be disabled by physical, intellectual or sensory impairment, medical conditions or mental illness.

The term handicap means the loss or limitation of opportunities to take part in the life of the community on an equal level with others. It describes the encounter between the persons with a disability and the environment. The purpose of this term is to emphasize the focus on the shortcomings in the environment and in many organized activities in society, e.g., information, communication and education, which prevent persons with disabilities from participating on equal terms.

Categories of the disabled

The disabled are people with one or more physical, mental and sensory impairments which limit one or more of the basic life activities such as seeing, hearing, talking, walking, using hands, understanding, learning,  communicating, etc. The following five categories were officially used in India before thePersons with Disability (Equal Opportunities, Protection of Rights and Full Participation) Act, 1995:

  1. The visually handicapped;

  2. The speech and hearing handicapped;

  3. The locomotor handicapped;

  4. The mentally retarded;

  5. The neurologically handicapped – in this category, the concern is restricted to only the cerebral palsied.

The Persons with Disabilities (Equal Opportunities, Protection of Rights and Full Participation) Act, 1995, identifies the following seven categories of disability, which will now be used in India :

  1. Blindness

  2. Low vision

  3. Leprosy cured

  4. Hearing impairment

  5. Mental retardation

  6. Mental illness

Sophistication vs. Simplicity in Definition

It is difficult to conceive of a rigid and precise definition acceptable to all those providers, who in order to ration the supply of their limited services in the face of immense demand, prefer to use definitions which exclude even genuine people with disabilities. On the other hand, it is equally difficult to accommodate the expectations of those who use a flexible definition to include even those at the borderline. There are hundreds of different disabilities and there are as many causes of these. Some people are born with disabilities, others become disabled later on in their lives. Some disabilities exhibit themselves only periodically like fits and seizures, others are constant conditions and are life-long. The severity of some stays the same. Others get progressively worse like muscular dystrophy and cystic fibrosis. Some are hidden and not obvious like epilepsy or haemophilia (impairment of blood clotting mechanism).

Some disabilities can be controlled and cured, others still baffle the experts. Thus, finding a consensus on the different and frequently varying definitions of disabilities, whether sophisticated or practical, has never been easy.

The definitions of mental retardation based on IQ levels are outmoded. It is not possible to decide retardation just on the basis of IQ levels since the IQ tests’ usefulness is limited to indicating how well a person may do in education and not how well he or she might do at work or life.  While it may be argued that there cannot be a universal blueprint of definitions, it is, however, necessary to have a fresh look at the definitions and include other categories such as disability due to epilepsy, learning disability, the definitions should be uniformly used throughout the country for the schemes of concessions / facilities provided for people with disabilities.

Americans with Disabilities Act, 1990 (ADA) classifies an individual as disabled if his/her physical or mental impairment “substantially limits one or more of the major life activities”.

In the Disability Discrimination Act, 1992 of Australia, ‘disability‘ in relation to a person, means-

  1. total or partial loss of the person’s bodily or mental functions; or

  2. total or partial loss of a part of the body; or

  3. the presence in the body of organisms capable of causing disease or illness; or

  4. the presence in the body of organisms causing disease or illness; or

  5. the malfunction, malformation or disfigurement of a part of the person’s body; or

  6. disorder or malfunction that results in the person learning differently from a person without the disorder or malfunction; or

  7. disorder, illness or disease that affects a person’s thought processes, perception of reality, emotions or judgment or that results in disturbed behaviour and includes a disability that:

    • presently exists; or

    • previously existed but no longer exists; or

    • may exist in the future; or

    • is imputed to a person.

According to the Disability Discrimination Act, 1995 of the British Government, a person has a disability for the purposes of this Act if he has a physical or mental impairment which has a substantial and long-term adverse effect on his ability to carry out normal day-to-day activities.

In order to apply the durability test, the British Act uses three different terms: loss of faculty, disability and disablement. These are meant to be separate concepts.

Loss of Faculty
Loss of faculty is any pathological condition or any loss or reduction of normal physical or mental functions of an organ or part of the body. A loss of faculty in itself may not be a disability but is an actual cause of one or more disabilities, e.g., the loss of one kidney.

A ‘disability’ means an inability to perform a normal bodily or mental process. It could either be complete inability to do something (such as walking) or it can be partial inability to do something ( such as one can lift weights but not heavy ones).

It is the sum total of all the separate disabilities an individual may suffer from. It means an overall inability to perform the normal  activities of life. The loss of health, strength and power to enjoy a normal life. While assessing an individual his/her physical and mental condition, inconvenience, genuine embarrassment or anxiety is taken into account.

Medical and Social Models 
There are two major models which explain disability and suggest approaches to deal with it in practical ways, the  medical model and social model.

The medical model views disability as a personal tragedy. Disability such as the impairment of limb, organ or function has traumatic physical and psychological effects on a disabled person. Disabled people, in this model, are regarded as people with limitations who cannot ensure a reasonable quality of life because of their impairment. The medical model expects individuals to find ways of adapting to society. It puts the duty of adjusting and adapting to the society of able-bodied or people and their environment on the disabled.

The social model presents disability as a consequence of oppression, prejudice and discrimination by the society against disabled people. It is  the society which constructs economic, social, health, architectural, legal, cultural and other barriers in order to deliberately prevent people with impairments enjoy full benefits of the society. The social model shifts the emphasis from a disabled individual to the society and its disabling attitudes and environment.