Positive language empowers. When writing or speaking about people with disabilities, there are two schools of thought. 

The language from the social model of disability separates impairment from disability. Impairment is defined as the functional limitations of bodies and minds and disability is defined as the barriers of unequal access, negative attitudes, discrimination and oppression. Hence, disabled person is accepted because it describes the person experiences oppression because of his or her impairment. I am disabled and disabled person is acceptable however, it is important to note that “the” disabled is never acceptable because word “the” makes a group of people “the other” which is exclusive.

In the intellectual disability community there is People First Language which defines it is important to put the person first. Group designations such as "the blind," "the retarded" or "the disabled" are inappropriate because they do not reflect the individuality, equality or dignity of people with disabilities. Further, words like "normal person" imply that the person with a disability isn't normal, whereas "person without a disability" or “non-disabled” is descriptive but not negative. The accompanying chart shows examples of positive and negative phrases. 

Affirmative Phrases Negative Phrases
person with an intellectual or cognitive impairment retarded; mentally defective
person who is blind, or visually impaired the blind
person who is disabled or disabled person the disabled; handicapped
person who is deaf the deaf; deaf and dumb
person who is hard of hearing suffers a hearing loss
person who has multiple sclerosis afflicted by MS
person with cerebral palsy  CP victim
person with epilepsy, person with seizure disorder Epileptic
person who uses a wheelchair confined or restricted to a wheelchair
person who has muscular dystrophy stricken by MD
person who is physically disabled

crippled; lame; deformed

unable to speak, uses synthetic speech dumb; mute
person with psychiatric impairment  crazy; nuts
person who is successful, productive has overcome his/her disability; is courageous (when it implies the person has courage because of having a disability)