Site Design for the Vision Impaired
If you've been in the search engine optimization business for any length of time you've heard the saying that, "search engines are blind, deaf and dumb," meaning that your web site should be designed so that the spiders can easily crawl through the site's pages and determine what the site is about. In other words, in order to be highly ranked organically, a web site needs to be crawlable and have excellent content; it does not need to look pretty.
However, since the majority of internet users rely on visuals to judge your site, making a site aesthetically pleasing, as well as easily navigable, keeps your visitors coming back. And, if the site has plenty of unique content and can be considered a subject matter expert, the site will probably do well in the rankings.
Did you know that about 19.4% or 1 in 5 people have a disability? I don't know how many of that percentage are vision impaired but it's worth considering that some of the visitors to your site will have some sort of vision impairment. This means that no matter how many pretty pictures or Flash movies you have on your site, they will not do your vision impaired visitors a lick of good if their screen readers or other software programs cannot accurately convey what is on the site. How then do you create a site that these users will be able to access and interpret?
Target Corp. is currently being sued by the National Federation for the Blind (NFB). The NFB, according to an article on msnbc.com, says that Target's web "site is inaccessible to blind Internet users." A Federal judge is allowing the suit to go forward even though Target is claiming that it is not subject to the ADA rules because the law only covers physical spaces, such as buildings.
The ADA was passed in 1990 before the internet really took off so Target may have a point but I don't think it's a strong one. Besides, why would you want to exclude a group of potential buyers from being able to navigate through your site? According to Chris Danielson of the NFB:
Accessing the Internet has been a 'huge boon' for blind people. It's allowed them to accomplish a great number of tasks on their own that would otherwise present difficulties or require the help of a sighted person, such as banking, buying plane tickets and shopping for things like groceries and music.
Designing a site for the vision impaired is not difficult but it does take some time. The main thing you need to keep in mind is that software programs for the vision impaired, like Jaws or Window-Eyes, actually read your page to the visitor. This means that when a page is loaded, the program will convert what it "sees" on the page and read it out loud to the user. The user can therefore navigate through the page using keyboard commands. In order for this to work, you need to have content for the program to read. If you have images on your pages, you need to have content accurately describing what the images are showing. This content is called the ALT tag and it is placed within the HTML tag that calls the image.
All government web sites are required by the Americans with Disabilities Act (ADA) to be accessible to the blind. Just as most sidewalks now have curb cuts (the ramps placed at corners) for people with wheelchairs to easily get across streets, web site designers need to provide a sort of electric curb cut for the vision impaired. This means making sure all your images have ALT attributes and that you have text links on each page that lead your visitors through the pages on the site.
This doesn't mean that your web site cannot incorporate drop down menus or Flash elements, it just means that you need to have an alternative to those items for the screen readers to read.
For example, look at the Bruce Clay site. The top navigation is in Flash, but all the menu items in that navigation are repeated at the bottom of the page with text links. The site also uses some neat Flash technology for the site map, but there are also text links on the same page, thereby ensuring that those without the visual acuity to see the Flash movies can still get around the site. This also means that the search engine spiders can easily spider the page as well.
Search engines and vision impaired visitors aren't the only ones who benefit from accessible websites. Kelly Pierce, the co-founder of "Digit-Eyes" says,
...when World Wide Web sites are accessible to people with disabilities, they are highly usable and accessible to everyone else as well. As the Web matures and grows in popularity, webmasters can be less and less certain that the visitor is using the latest version of Navigator or Explorer. In other words, accessible Web design also assures "backwards compatibility" with older Internet browser software. But it's not just older technology that benefits from good design. Many newer ways to access the internet benefit greatly from universal design, people may be online with their PalmPilot, or on WebTV, or browsing using their telephone. The closer companies and other organizations design their sites to HTML standards, the more accessible they are to people with disabilities and everyone else.
Two other web sites that I have found useful are the Government's Section 508 web site and the Information Technology Technical Assistance and Training Center web site.
Usability in your site design may not be a matter of U.S. law, yet, but it should be considered part of your SEO web design gospel.