How a blind is identified by an iris recognition?

I am presenting a paper in Biometrics which involves iris recognition and I want to know how a blind can be identified by this system.

How a blind is identified by an iris recognition?
as long as the blind person still has their own eyes and doesn't have to wear dark glasses there shouldn't be a problem with that, because the iris is still unique from person to person, whether the pupil reacts to light or not. if you mean how an iris recognition system can tell a sighted person from a blind one i dare say it wouldn't always be possible. some types of blindness are caused by diseases of the eye, and with those types there is a high likeliness that the pupil will not react to light. the recognition system could then use the staticness of the iris to identify a person as blind. the same thing would happen if a blind person has had their eyes removed and replaced by cosmetic prosthesis. if, however, the cause of the blindness is in the brain and the eyes themselves are perfectly healthy, or the person is wearing dark glasses, the recognition system will not be able to tell if they are blind or sighted.

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