In article ,
Andrew McKay writes:
I don't know about these things but I wouldn't have made an assumption
that just because people are blind it would limit their ability to be
tested.

Iris scanning includes a check that the pupil responds to
changes in light level, so it isn't fooled by holding up
a photograph of someone's iris. That reflex doesn't always
work in blind people (actually I know an otherwise normally
sighted person for whom it doesn't work either).

Also, iris testing? I thought the ID cards relied upon a fingerprint of
the back wall of the eye? The Iris is at the front.

Anyone trying to leave their fingerprint on the back of my
eye will find themselves coughing up their testicles...

--
Andrew Gabriel