July 1969 PAPERBACK LIBRARY mass market paperback, Paul Corey (Do Cats Think? Notes of a Cat-Watcher). What would happen to an intelligent, sighted inhabitant of Earth marooned on a planet inhabited by an unsighted people, with a technology equal or superior to his? - Google Books
Another book that asks what it is to be human. A billionaire playboy crash lands on a mysterious planet. The human like inhabitants do have have or know what sight is. They mistake him for an animal and send him away to be kept at a farm. He must escape with help from the chief scientists daughter, who he teaches to "see" with an invention of his. But seeing is heresy...