For 133 years, one company has produced nearly every educational tool used by legally blind students throughout the United States.
The American Printing House for the Blind in Louisville, Kentucky, is the world's largest publisher of everything from books to maps to "talking books" specially designed for the blind and visually impaired.
The favorite bible of the late Helen Keller, the renowned blind and deaf author and lecturer, was printed at the American Printing House.
The company's in-house museum even holds the world's first-known book for the blind. It employed actual letters - A, B, C, and so forth - raised above the surface of the page.
It was printed in France in 1786, just before Frenchman Louis Braille invented his system of raised dots that are readable with one's fingers.
Visitors to the museum can try their hand at producing braille using a special typewriter. And they can see styluses and slates developed to help the blind write on paper.
Public donations pay for the company's production of braille versions of popular magazines, including Reader's Digest, Newsweek and the Weekly Reader for young people.
The American Printing House even churns out braille versions of federal tax forms, periodic tables of the elements, and instructional manuals on such topics as how to crochet yarn.
And the Library of Congress in Washington pays it to produce about 500 audio "talking books" each year.
Like any publisher, the American Printing House For The Blind proofreads its books before it mass-produces them.
That requires two people. A blind person scanning the braille with his or her fingers speaks the words and punctuation to a sighted person, who checks their accuracy against the original, written text.
Braille books are still the showcase product. American Printing House president Tuck Tinsley says that for a blind as well as a sighted reader, there is nothing like having a book to hold and read at one's own pace.