When was the blind guide/Seeing Eye Dog "invented"?

The other day a blind man with a guide dog (“Seeing Eye Dog”, IIRC, is a trademarked name for one particular trainer’s dogs) walked by me. As usual, I was blown away by the animal’s discipline and obedience. But then I wondered; when did they “invent” this role for dogs?

Obviously, dogs have been our friends for millennia and they’re protective of their owners, but who invented the current pattern for training and using guide dogs? It’s a remarkable achievement.

http://www.seeingeye.org/GuidedTour.asp?sc=hs

http://www.seeingeye.org/aboutus.asp?sc=ps#1