visual impairment vs disability

visual impairment and disability both are nouns.

Word	Noun	Adjective	Verb	Adverb
visual impairment	Yes	No	No	No
disability	Yes	No	No	No

As nouns, disability is a hypernym of visual impairment; that is, disability is a word with a broader meaning than visual impairment:

visual impairment: impairment of the sense of sight
disability: the condition of being unable to perform as a consequence of physical or mental unfitness

Other hypernyms of visual impairment include disablement, handicap, impairment.

visual impairment (noun)	disability (noun)
impairment of the sense of sight	the condition of being unable to perform as a consequence of physical or mental unfitness