Tall, fit, and looking younger than his 61 years, Bill Henderson stands in a sunlit gallery in Boston that showcases art by people with physical and developmental disabilities, like the students in the urban elementary school he ran as principal for 20 years.
An experiment in inclusion that mixed disabled students with their non-disabled peers, the Patrick O'Hearn School became a model for inclusion schooling.
During his career Mr Henderson received countless accolades. So widely respected was he that, when he retired, the Patrick O'Hearn School was renamed the Dr William W Henderson Inclusion School.
Now, Mr Henderson works as a consultant for initiatives such as this art programme. But he can't see the colourful works on the walls. As he has been for much of his career as an educator of students with disabilities, Bill Henderson is blind.
His disability forced him to be organised and to collaborate - two qualities he says are vital for the kind of team effort required to educate disabled and non-disabled students in the same schools.
But it was the suggestion that he should quit and apply for disability retirement - first by the doctor who diagnosed him with retinitis pigmentosa when he was 24, then by a supervisor in the middle school where he was teaching a few years later - that caused him to use his skills in inclusion schooling.
"Having someone tell me to go on long-term disability when I was 30 pissed me off," he said. "So I relate to parents who are told, 'Your kids can't do this'."
Thus, instead of leaving education, Mr Henderson took the job of principal at the Patrick O'Hearn School in Boston's multi-ethnic Dorchester neighbourhood, which serves children aged five to 11, a quarter of whom are disabled.
Now Mr Henderson has written a book about what he has learned, The Blind Advantage: how going blind made me a stronger principal and how including children with disabilities made our school better for everyone, out this autumn from Harvard Education Press.
He writes that while students with disabilities are often blamed for lowering standards and performance in schools, including them can improve teaching and learning for everyone.
All are held to equally high standards. "The worst thing you can do is babysit them. You have to make them work hard," he said.
There were missteps. Mr Henderson writes that, after reprimanding a teacher privately in her classroom, he walked out of the door - and straight into a cupboard. At a student performance, he accidentally sat in a parent's lap.
But Mr Henderson's blindness "really informed his understanding of the fact that disability is only one aspect of any person's experience and capability," said Charles Washburn, director of VSA, a scheme that develops arts education for people with disabilities. "It's only the restrictions that others assign from the outside that really present any barriers."