Introduction to Vision Impairments

3.2.3. Braille input and output devices as a tactile substitute for persons with visual impairments

Although only 10 to 15% of individuals who are blind can access braille, it is the most widely used tactile substitution tool for persons with vision impairment. Very few people with vision impairment learn to use it because other alternatives such as talking books are more desirable for people who become blind later in life.
Braille is a script which can take the form of any language and any language can be translated to its very own Braille equivalent. It is basically a combination of embossed dots which takes the form of different alphabets when the rows and columns of dots are changed.
From being manually punched by hand, Braille has come a very long way to now being typed to refreshable modes.  

Here is a quick story of how Braille has evolved over the years.

Braille can be produced in the following modalities:

1. Embossed braille on heavy paper 
2. Refreshable braille display as a computer input and output system

For computer users who are familiar with braille, refreshable braille displays can be more effective than screen readers. However, a combination of approaches may be most effective with braille and speech combined. If done thoughtfully and carefully, the hardware and software designed for braille can be used together with that developed for screen reading with speech synthesis.