Tools and hints for webmasters
Overview: Web site standards
to help sight-impaired visitors
There are approximately 30 million people in the Americas who are
sight-impaired, of whom over 2% are totally blind. 1 Unfortunately,
many, perhaps most, Internet websites are optimised for fully sighted persons.
Sites may involve sound, but generally rely on images and text to convey their
message to their visitors. Some of the text and images can be quite small and
difficult to understand to a person who is sight-impaired.
Helps for sight-impaired persons include:
The readers and displays can only work effectively if the website being surfed
meets certain standards. For example, these devices cannot interpret images. Thus, they
need the "alt=" coding filled in on every image to tell the user what the image
- Screen enlargement software: These are programs that expand
a monitor's display in order to make pages easier to read.
Some also change the screen colors and contrast. Many
individuals with moderate loss of sight can benefit from this software. 2
Some browsers (e.g. Mozilla Firefox, Google Chrome,
Internet Explorer, etc.) can "zoom in" when the Ctrl key is held down and the +
key is pressed one or more times.
- Screen readers: These read text as displayed on a
monitor screen and translate the words and punctuation into speech.
- Refreshable Braille displays: (a,k,a, Braille terminal).
This is an electro-mechanical device that can display characters in the form of
a Braille cell of six dots. Each cell represents one letter (A to Z), a digit (0
to 9), punctuation marks (apostrophe, period, comma, semicolon, exclamation
point, opening quotation mark, closing quotation mark, parenthesis, or hyphen)
or control cell (capital letter follows, or number follows). The device presents
18 to 80 cells to the person, each containing from one to six raised dots.
Persons who can read Braille can then scan the cells with her/his fingertips. 3
- Rotating wheel Braille display: This is a new design for a
Braille terminal that is currently under development as of late 2008. It raises
dots on the edge of a slowly spinning wheel under the user's stationary finger. 3
U.S. government accessibility standards:
According to a federal government website at: www.Section508.gov:
"In 1998, Congress amended the Rehabilitation Act to require
Federal agencies to make their electronic and information technology accessible
to people with disabilities. Inaccessible technology interferes with an
individual's ability to obtain and use information quickly and easily. Section
508 was enacted to eliminate barriers in information technology, to make
available new opportunities for people with disabilities, and to encourage
development of technologies that will help achieve these goals. The law applies
to all Federal agencies when they develop, procure, maintain, or use electronic
and information technology. Under Section 508 (29 U.S.C. ‘ 794d), agencies must
give disabled employees and members of the public access to information that is
comparable to the access available to others." 4
The federal government's access guidelines for web sites are based on the Web Accessibility Initiative of the World Wide Web
Consortium. Their "Summary of Section 508 standards" states:
"Many of these provisions ensure access for people with vision
impairments who rely on various assistive products to access computer-based
information, such as screen readers, which translate what's on a computer screen
into automated audible output, and refreshable Braille displays. Certain
conventions, such as verbal tags or identification of graphics and format
devices, like frames, are necessary so that these devices can "read" them for
the user in a sensible way. The standards do not prohibit the use of web site
graphics or animation. Instead, the standards aim to ensure that such
information is also available in an accessible format. Generally, this means use
of text labels or descriptors for graphics and certain format elements. (HTML
code already provides an "Alt Text" tag for graphics which can serve as a verbal
descriptor for graphics). This section also addresses the usability of
multimedia presentations, image maps, style sheets, scripting languages, applets
and plug-ins, and electronic forms." 3
Canadian government accessibility standards:
The Treasury Board of Canada Secretariat has published "Common Look
and Feel Standards for the Internet" (CLF). All "public facing" Government of
Canada web sites must meet this standard. 5
If requirements for non-government, commercial, non-profit, and/or personal
web sites are introduced in Canada, they may well be partly based on parts of
the CLF standards.
Which web sites are required to meet Section 508 standards?
According to the U.S. federal government's site "Summary of Section 508 Standards"
as of 2008-NOV-15:"
"The standards apply to Federal web sites but not to private sector web sites
(unless a site is provided under contract to a Federal agency, in which case
only that web site or portion covered by the contract would have to comply)."
Accessible sites offer significant advantages that go beyond access. For
example, those with "text-only" options provide a faster downloading alternative
and can facilitate transmission of web-based data to cell phones and personal
digital assistants. 6
However, the Computing Unplugged (CU) newsletter reported that on 2008-AUG, the
retail giant Target settled a $6 million federal class action suit brought by
the National Federation of the Blind because the Target website did not provide full and
equal access to sight-impaired persons.
CU wrote: "Combined with
similar federal requirements it is now essentially necessary for all [American]
companies' websites to be fully accessible to the 21.2 million sight-impaired."
The CU and government statements appear to be in conflict; at
least one appears to be in error.
How to check a HTML file for compliance:
To determine how easy your website's navigation is for
sight-impaired persons, several free websites are available:
Deque Systems Inc. has an accessibility analysis tool that
can analyze a single page for accessibility. See: http://worldspace.deque.com/
WebXact provides a free service at: http://webxact.watchfire.com/ It analyses a single page "...of web
content for quality, accessibility and privacy issues."
- The Web Accessibility Evaluation Tool (WAVE) also analyses a single page at http://wave.webaim.org.
- Bobby is a "public service offered by CAST that analyzes web pages for
their accessibility to people with disabilities as well as their compatibility with
various browsers." See: http://www.cast.org/
- Colorblind Web Page
Filter is a fascinating free service at: https://www.toptal.com/. It shows how a home page, essay, menu, etc.
appears to a person with various types of colorblindness. Generally, if you use
dark lettering on a light colored background, a colorblind person will have fewer
problems accessing it.
Certain website WYSIWYG editors -- e.g. Microsoft® Expression® Web and
Adobe® Dreamweaver® -- have accessibility checkers:
Expression Web's Tools pull-down menu has an "accessibility
reports" option that can scan the current essay, all open essays, or
essays from the entire site for compliance with WCAG and Access Board
Section 508 standards. 7
Dreamweaver generates similar reports. It can also be set up
to prompt the user for an alternative text whenever an image is added to the
document, or for appropriate labeling information when a form is added etc. 8
WebAIM 9 has published a handy
checklist for Section 508 compliance, with helpful guidelines that define
whether an file will pass or fail. 10
The following information sources were used to prepare and update the above
essay. The hyperlinks are not necessarily still active today.
- "Magnitude and causes of visual impairment," World Health Organization,
2004-NOV, at: http://www.who.int/
- "Screen Enlargement Software," Division of Blind Services, Florida, at: http://dbs.myflorida.com/
- Refreshable Braille Displays," Division of Blind Services, Florida, at: http://dbs.myflorida.com/
- "508 Law," Section508.gov at: http://www.section508.gov/
- "Implementation of new CLF 2.0 Standards - Qs and As," Treasury Board of
Canada Secretariat, at: http://www.tbs-sct.gc.ca/
- "Web-based Intranet and Internet Information and Applications
(1194.22)," Section 508, at: http://www.section508.gov/
- "How to Make Accessible Web Content Using Microsoft Expression Web,"
WebAIM, at: http://www.webaim.org/
- "How to Make Accessible Web Content Using Dreamweaver," WebAIM, at: http://www.webaim.org/
- WebAIM is an initiative of the Center for Persons with Disabilities and
the Utah State University. See: http://www.webaim.org/
- "WebAIM Section 508 Checklist," WebAIM, at: http://www.webaim.org/
Copyright © 2008 to 2016 by Ontario Consultants on Religious Tolerance
Initial posting: 2008-NOV-15
Latest update and review: 2016-AUG-23
Author: B.A. Robinson