From the official Seeing Eye website:
"Quite frequently, people ask us, "How can I become a Seeing Eye instructor?" Staff instructors are full-time employees who hold college degrees from various fields of study and have successfully completed three years of specialized on-the-job training. They relate well to dogs and people and are physically fit, since their jobs are physically demanding and involve working outdoors in all weather. Some of our current instructors came from teaching, business consulting and rehabilitation fields. Some were in the military and worked with dogs before, and many started out as kennel assistants here at The Seeing Eye."