Mental Retardation: Mental retardation means sub average general intellectual functioning associated with mal–adaptive behavior, occurring in the developmental period. Mental retardation is divisible into the following four categories

• Mild retardation IQ – 50 – 70.Moderate retardation IQ – 35 – 49.
• Severe retardation IQ – 20 – 34.
• Profound retardation IQ under 20.

In the new Law – Persons with Disabilities (Equal opportunities, Protection of Rights and Full Participation) Act, 1995, unless the context otherwise requires:
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 – –total absence of sight, or visual acuity not exceeding 6/60 or 20/200 (snellen) in the better eye with correcting lenses –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, 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 – 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, manifest deformity and paresis but having sufficient mobility in their hands and feet to enable them to engage in normal economic activity, extreme physical deformity as well as advanced age which prevents 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 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 per cent 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 assistive device.