Access to text for blind and severely visually impaired people can be achieved by converting the text into a dot pattern called Braille comprised of up to eight tactile dots. This system was invented by Frenchman Louis Braille in the 19th century and subsequently spread around the world, becoming the equivalent of printed text for sighted people.
In the basic arrangement, characters in Braille consist of six dots in a pattern of two columns and three rows. Each of these dots can be set or unset. A set dot is raised and can therefore be perceived with a stroke of the reader's finger. Different combinations of set and unset dots represent different characters.
Braille characters need much more space than their printed counterparts. Because of this, Braille books are often written in a complex system of abbreviations and contractions. On the other hand, Braille on computers is commonly enhanced by adding a fourth row of dots, so a single character consists of up to eight dots.
Refreshable Braille Displays
To read text from a digital source, blind people currently use refreshable Braille displays. These devices display Braille characters as a pattern of mechanically raised dots that can be recognized with the fingertip.
For technical reasons, these devices can only show one line of Braille text at a time. For mobile Braille devices, this line has to be kept short and thus the text will be potentially tedious to read. Desktop devices with longer lines are frequently bulky and very expensive.
This is where Tetragon will change the game by providing a device that will be both portable and capable of showing long lines of text.