Web accessibility
For people who are blind or have low vision the World Wide Web has greatly improved their ability to access information and to communicate. This also applies to many people with auditory, physical, speech and cognitive disabilities.
The web is now one of the foremost sources of information, entertainment and interaction for nearly everyone. As a resource it is used for education, employment, government, commerce, health care, recreation, and more. However, many web sites have barriers to accessibility that make it difficult or impossible for many people with disabilities to use.
For people who are travelling or booking tickets, or who want to find information about venues, places or events, the web is often the first place they will access.
Because email is text-based and relatively easy to learn and to use, it has been very useful for many people with disabilities. For a web site to be accessible, a person with a disability must be able to perceive, understand, navigate, interact with, and contribute. This is also very important for older people when their abilities change due to ageing.
Many blind people rely on screen readers to access the web; these screen readers are software that reads text on the screen and outputs this information to a speech synthesizer or braille display. Some people who are blind use text-based browsers or voice browsers, instead of a graphical browser. They often use rapid navigation techniques such as tabbing through the headings or links on web pages rather than reading every word on the page in sequence.
Some people with low vision use extra-large monitors, and increase the size of the fonts and images. Others use screen magnifiers or screen enhancement software. Some people need to have specific combinations of text and background colours, or choose certain typefaces that are especially legible for their particular visual impairment.
People with colour blindness sometimes need to use their own style sheets to override the font and background colour.
It is possible to design and build web sites that allow all of these systems to be used by a person who is blind or has sight problems.
Many people who are deaf or hard of hearing rely on captions for audio content to access the web. They may need to turn on the captions on an audio file as they browse a page.
When a person has physical disabilities such as weakness or limitations of muscular control they may use a pointing device such as a head-mouse, head-pointer or mouth-stick. They may use voice-recognition software or other assistive technologies. When designing web sites that allow for this type of disability, a facility to allow more time for response is important. Also forms that can be tabbed through in a logical order will help.
Many website designers work on the philosophy that the user's browser is no more than a year old. In the case of disabled users, it is likely to be considerably older than that, so there can be a problem with legacy systems.
Guidelines have been produced for how to design accessible websites, but these guidelines are widely ignored by commercial organisations. So some websites are accessible, but these tend to be ones belonging to government departments. Many of the popular websites, for buying tickets, shopping and home banking, are still largely inaccessible.
Recommendations for a web site to be accessible include:
- Use the alternative text (alt) attribute to describe the function of images and animations.
- Provide captioning and transcripts of audio, and descriptions of video.
- For hypertext links, use text that makes sense when read out of context.
- For page organisation, use headings, lists and consistent structure. Use cascading style sheets for layout and style where possible.
- Summarise in text the significance of graphs and charts.
- For tables, make line by line reading sensible. Avoid using tables for column layout.
- Use relative sizing instead of fixed (e.g. for fonts, tables).
Go to Tiresias Web Guidelines