It's worth pointing out that there is more to accessibility than screen readers or braille output for the seriously visually impaired. It's also important to support the following:
- mild visual impairments: large fonts and magnification
- for the deaf: visual equivalents of sound effects, and subtitling of videos
- for those with motor/dexterity impairments (including RSI): speech input, alternative input mechanisms (e.g. tongue, foot, blowing), modified input mechanisms (alternative pointing devices)
- for those with speech and language impairments: alternative input/output, communications boards (i.e. use computer to communicate with others interactively through symbols) - inconsistent speech can be a problem for speech input though.