Light for the blind: A history of the origin and success of Moon’s system of reading (embossed in various languages) for the blind.

Moon became totally blind at the age of 22. He taught other blind people and devised a simplified form of roman letters, embossed on paper, for use by blind readers. This was in 1845, and two years later he published his first book in Moon type. Digital facsimile from Google Books at this link.