Most legally blind people 85 percent do not use computers. The primary audience for such applications is those who have difficulty reading because of learning disabilities or language barriers. Screen reader choice is contentious: differing priorities and strong preferences are common. The movement towards greater web accessibility is opening a far wider number of websites to adaptive technology, making the web a more inviting place for visually impaired surfers. Only a small fraction of this population, when compared to the sighted community, have Internet access.

Screen readers are a form of assistive technology potentially useful to people who are blind, visually impaired, or learning disabled, often in combination with other AT such as screen magnifiers. Almost 13 percent of those deemed legally blind, by any measure, have no vision. Access technology such as screen readers and Screen magnifiers enable the blind to use mainstream computer applications. The open source GNOME desktop environment long included Gnopernicus and now includes Orca. More and more, screen readers are being bundled with operating system distributions. This interpretation is then represented to the user with text-to-speech, sound icons, or a braille output.

While Apple Mac OS X includes VoiceOver, a more feature-rich screen reader. Linux distributions for the blind include Oralux and Adriane Knoppix. The Macintosh OS also comes with a built-in screen reader, called VoiceOver. There are also open source screen readers, such as the Linux Screen Reader for GNOME and NonVisual Desktop Access for Windows.

Therefore functionality remains limited compared to equivalent desktop applications, the major benefit is to increase the accessibility of said websites. Later versions of Microsoft Windows include an Accessibility Wizard and Magnifier for those with partial vision, and Microsoft Narrator, a simple screen reader. The rest have some vision, from light perception alone to relatively good acuity. The latter developed in part by Knopper who has a visual impairment. Screen readers can be assumed to be able to access all display content that is not intrinsically inaccessible.

Web browsers, word processors, icons and windows and email programs are just some of the applications used successfully by screen reader users. Nevertheless, using a screen reader is, according to some users, considerably more difficult than using a GUI and many applications have specific problems resulting from the nature of the application. A screen reader is a software application that attempts to identify and interpret what is being displayed on the screen. Experimental approaches in sensory substitution are beginning to provide access to arbitrary live views from a camera.

Recent versions of Microsoft Windows come with the rather basic Narrator.

Comming month volunteer Anthony Loeff is testing digital tools for visually impaired people The console-based Oralux Linux distribution ships with three screen-reading environments: Emacspeak, Yasr and Speakup. A persons choice of screen reader is dictated by many factors, including platform and the role of organizations like charities, schools, and employers.