Computers are just as important to people who are blind as they are to the rest of us. But current systems of translating screen displays into the raised dot letters of the Braille alphabet are pretty clumsy: They require nearly 500 moving parts called actuators to display entire pages at a time. Now comes a device, invented by John Roberts and colleagues at the National Institute of Standards and Technology (NIST) in Gaithersburg, Md., that uses as few as three moving parts.

A stream of Braille letters formed along the edge of a rotating wheel is the basis for the new display. Each turn of the wheel presents a new line of Braille text. Fingers held just above the rotating wheel read the dots as they go by. A commercial Braille wheel using this design could be about the size of a portable CD player and much cheaper than current displays. Software has been written for the wheel to display scrolling text from electronic books.