Designing for Access to the Web for Blind and Visually Impaired Users

February 25, 1998

1. Introduction

For those who have access, the World Wide Web is a powerful resource for education, commerce, social interaction, arts, and entertainment. Unfortunately, not everyone has access to the full range of resources available. Blind and visually impaired users have very limited access. Many barriers limit this group's ability to move through the Web. This paper will discuss the nature of these barriers and present some ways to overcome them.

2. Background

When the Internet was first developed, the standard computer interface was still largely text-based. Blind and visually impaired computer users could easily gain access to the Web's resources using technology, such as screen readers and screen magnifiers (both will be explained in more detail later). The Internet represented a huge step forward for these users as it provided them with access to previously unavailable information. For example, Project Gütenberg provided access to hundreds of literature classics without the problems of finding the works in Braille or hiring someone to read the works to them.

The advent of the graphical user interface (GUI) and the World Wide Web, however, changed the nature of the Internet. The emphasis shifted from the distribution to the presentation of information. This is not to say that content suddenly became unimportant, simply that much more emphasis was placed on the way this information was presented. Today, the Web is a mix of graphics, sound, video, animation and text -- all designed to make sites more appealing to users. For users with good vision, fast connection speeds, and the latest computer hardware and software, the Web has become a much more exciting place. For those without these advantages, gaining access to the content on the World Wide Web has become increasingly difficult.

3. Improving Access

Providing blind and visually impaired users with access to information online is no longer the sole task of the developers of adaptive or assistive technology. These developers continue to be involved, but those who set the standards for distributing information on the Web and those who design the sites that present information must also be included. The following is a brief look at the technology available today and the steps that are being taken by those who set the standards. The focus will be on the steps that Web designers can take to ensure that blind and visually impaired people have access to the information presented.

4. Adaptive or Assistive Technologies

The most commonly used assistive technologies for blind and visually impaired people are screen magnifiers, screen readers, and refreshable Braille pads.

4.1 Screen Magnifiers

Screen Magnifiers for computers are relatively simple software programs that can be purchased for approximately $30 US. Demo versions can be downloaded from the Web free of charge. This technology magnifies the text on the screen so that users with poor vision can read text that is otherwise too small. Most of these programs allow users to magnify the text by a factor of 2 to 16 times the original text size.

4.2 Screen Readers

Screen Readers read text on computer screens and translate the written text into speech using a voice synthesizer. These devices work well with simple text, but current screen readers stumble over unusual punctuation and text presented in columns. These devices allow blind and visually impaired users to ‘read' up to 400 words per minute of simple text on the Web. They currently range in price from $100 to $600 US. The speech synthesizers must be bought separately for $100 to $1 000 US.

4.3 Refreshable Braille Pads

Refreshable Braille pads work in a similar manner to screen readers, except that the text on the screen is translated into Braille rather than speech. The pads are roughly the size of a keyboard and are composed of hundreds of pins that are raised and depressed mechanically. These devices are much more expensive than screen readers (between $8 000 and $15 000 US), but have the advantage of allowing the user to scan full sections of a document easily. Screen readers read the text slowly from left to right, one word at a time. This can be very frustrating for someone who wishes to study a piece of writing carefully.

5. Web Accessibility Initiatives

Standards exist (in North America at least) to ensure that people with disabilities have access to all public buildings and services. It would be illegal to design a public library that did not provide ways for people with physical disabilities to access the library's collection. Many groups feel that similar standards should be in place on the Web. The World Wide Web Consortium (W3C), the Royal National Institute for the Blind (RNIB), disability organizations around the world, and North American and European governments are all involved in setting standards for the accessible design of Web sites. The group with the clearest position is the W3C.

The W3C's stated position is:

All the protocols and languages we issue as recommendations should meet or exceed established accessibility goals. In addition, we will actively encourage the development of Web software and content that is accessible to people with most disabilities.

(http://www.w3.org/WAI/Activity.html)

The W3C also has a list of requirements that must be met by everyone involved: