So, would you mistake a blind man's stick for a samurai sword?

A police officer demonstrates the firing of a Taser (Rex Features)

An architect who was left blind after suffering a stroke was shot in the back by a police officer with a 50,000-volt taser gun after allegedly mistaking his white stick for a Samurai sword.

Colin Farmer, 61, was making his way at a "snail's pace" to meet friends at a pub in Chorley, Lancashire, as unbeknown to him police were chasing reports of a man walking through the town armed with the deadly martial arts weapon. He described how he felt "trapped in a nightmare" after he heard shouts from behind. "I certainly didn't know they were police – I thought I was going to be attacked by hooligans. The next thing they firing a taser at me." Mr Farmer was taken to Chorley Hospital for treatment after the incident last Friday and is now considering legal action.