There is no reason to avoid the word blind in referring to a person who is sightless or whose vision is so severely restricted as to be useless for ordinary purposes. As with deaf—but unlike cripple—the substitution of a euphemistic expression for blind could itself be objectionable if perceived as implying that blindness is too piteous a condition to be stated in plain language. In particular, you should not substitute visually impaired for blind except in referring to a range of vision problems that includes less than total or legal blindness.
