First of all... what is a web browser?

A web browser is the software program you use to view websites. Popular web browsers include:

These browsers are described as 'graphical' browsers, which means they display graphics, sound and other media. Users navigate their way round web pages by clicking buttons, icons and menu options.

There's also 'non-graphical' browsers, like Lynx and Links (yes, two text-based browsers with remarkably similar names but completely unrelated). Viewing web pages on non-graphical browsers means there's no graphics (and usually no sound, colours or other media) just plain text presented in a simple, structured format. Users navigate their way around web pages by keyboard.

In essence, all browsers do the same thing

Whether it's graphical or non-graphical, a browser's sole aim is to deliver the content of web pages. How this content appears depends on the end user, for example, someone browsing this site on a mobile phone will get a simplified version, with few images and small page sizes. Whereas someone accessing this site using a modern, graphical browser on a wide screen monitor, will get all the visual flair as intended for that browser type. Equally, when a blind person 'reads' this web page with a screen reader, they won't necessarily see the page it but they'll be able to 'hear' it.

The ideal is that every user gets at least the website's textual content. This is called accessible web design.

So, how does a blind person read this page? →

Screen readers

With most browsers screen reader technology can be integrated to help people with little or no functional vision 'read' websites. Unlike graphical and non-graphical browser output, described above, the web page content from a screen reader will usually be audible or delivered as Braille. In some cases, users of screen readers don't even have a screen!

The audible output from a screen reader is basically an electronically generated 'recital' of a web page, i.e. the blind person listens to the web page rather than reads it. Commonly, they use a keyboard to work through a web page. The screen reader software lets the user know when they are focussed on a link or a heading by reading out the content accordingly.

The Braille output is a series of raised dots that a user can pass their fingers over in order to 'read' the web page content. The dots don't appear on the screen but on a clever device called a Braille Reader.

People with some vision may use screen magnifiers rather than a screen reader. Screen magnifiers come in two forms, software that is installed on a computer or a large-scale magnifing glass that sits in front of the computer screen.

There's a collective term used to describe all the different technologies that can be used in conjunction with web browsers to extend their functionality: Assistive Technology (AT).

More AT please →

More assistive technologies

For people who can't use a keyboard or mouse or who have reduced physical ability, there's a wide range of assistive technologies available to help them access the web through their browsers. Here's a few:

• Voice browsers - voice activated browsers allow voice-driven navigation, resulting in a user speaking the name of a link and the computer responding
• Haptic devices – allow a user to interact with a computer by receiving tactile feedback, usually through vibrations or some type of movement pattern
• Head mounted pointer – this is a device that uses optical sensors to detect head movement that is then relayed to the mouse pointer on screen
• Lomak - a light operated mouse and keyboard (more information at The Letter)
• Touch screens – allow users to physically select a link by touch rather than with a mouse pointer
• Large screens – for visually impaired users
• Trackballs – operate like a mouse, except the need to grip the trackball is removed
• Ability switches – are operated by foot, head, an eye blink or a breath to achieve similar results from a mouse click
• Ergonomic keyboards – unusually-shaped keyboards for almost any scenario
• Neural interfaces – small electrical signals can be acquired from the user's muscles, eye movement or brain waves to control a mouse pointer; it's not science-fiction even though it sounds like it!
• Word prediction programs – a common tool found on mobile telephones and word processors is also extremely useful for those with dexterity limitations in terms of keyboard input

Want to know more about AT? →

Useful links

If this has whet your appetite for more info on browsing the web and AT here's a few useful links:

• A web challenge - to see how you get on without a mouse
• What is a web browser? (video) - Google asked a bunch of people this question
• The most important program on your computer (video) - guess?
• A definition of Assistive Technology
• Voice browsers
• Screen magnifiers
  
• WebbIE - a web browser for blind and visually-impaired people
• NonVisual Desktop Access (NVDA) - a free and open source screen reader for Windows
• Fangs – a screen reader emulator
• Ergonomic keyboards
• Large type keyboards
• Alternative pointing devices
• Braille and low vision aids
• More keyboards and alternative input devices
• A comprehensive directory of sources of input technologies - produced by Bill Buxton