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Citizens With Disabilities - Ontario


As Web evolves, blind left behind

By Tim Spangler
Chicago Defender, IL, February 09, 2007

The last time Ray Campbell tried to buy Cubs tickets online, asked him to enter the text in a distorted image in order to prove that he was not a robot programmed to automatically buy tickets for scalpers. .

The only problem: Campbell couldn't read the text in the image. In fact, he couldn't see it at all - he's been blind his entire life.

"All I want to do is buy tickets and I can't do that, because there's this verification and they have not provided an audio link to it," Campbell said.

For America's nearly 2 million blind or visually impaired Internet users, problems like these can prevent them from taking advantage of all the Web has to offer.

"The two challenges with Web accessibility are not just being able to access the site, but being able to use the site," said Leah Gerlach, director of counseling at the Diecke Center for Vision Rehabilitation in Wheaton.

Gerlach said the growing use of multimedia video on Web sites creates a significant accessibility challenge, saying that Internet video can confuse the screen reading software that blind and visually impaired people use to browse the Internet.

Blind Browsing

Blind and visually impaired people use special software called screen readers that "speak" to them in a synthetic voice what is happening on the screen.

When browsing a Web site, a screen reader examines a page's code and determines how the page is laid out and what links are on it, then reads the content of the page to a user.

Screen readers rely on explanatory text, defined by webmasters, to interpret images. Because of this, the World Wide Web Consortium, which sets Internet standards, requires developers to define alternative text for every image on a page.

Multimedia content, like Adobe Flash, is unintelligible to screen readers and is skipped entirely when the page is read. Sites that rely heavily on Flash should be sure to offer accessible, text-only versions of their pages. Screen reading software uses text-to-speech conversion, machines that translate on-screen text to Braille or a combination of both to present a Web page to a blind or visually impaired user.

The challenges

Campbell is a technician at the assistive technology help desk at the the Chicago Lighthouse, an organization for the blind and visually impaired. A former software engineer at Lucent Technologies, he now takes calls from blind and visually impaired people across the U.S. and Canada and helps them solve computer problems and navigate Web sites.

Campbell identified what he said are the Web's three major accessibility problems:graphics without descriptive text, required plug-in installations and visual registration tests, called captchas, an acronym for "Completely Automated Public Turing Test to Tell Computers and Humans Apart." Captchas are particularly troublesome when it comes to accessibility.

Why captchas?

Many major sites require users to verify that they are actually human - not automated robots. By presenting the browser with a captcha - an image of distorted text that is difficult for a computer to decode - and asking the user to enter the text they see in the image, robots can be blocked from the site while human users who can see the text are given access. Campbell said that captchas can be made accessible by using audio clips in addition to images to verify users as human. Some sites, like, already do this.

What works, what doesn't

Blogging, a growing Internet phenomenon, is still largely text-based and tends to be more screen reader friendly than other applications.

"My experience has taught me that [blogging] is pretty accessible," said Campbell, who keeps his own blog on LiveJournal.

"Screen readers can handle a lot of the current techniques that are being used in Web design," Campbell said, as long as designers take extra care to make their sites accessible. These include avoiding the use of images to display text, providing audio narration for videos and offering text-only versions of pages with multimedia content.

As interactive, multimedia Web sites become more prevalent, blind and visually impaired users might find themselves behind the curve as designers forgo accessible pages for glitzy ones and screen reading software lags behind, said Leah Gerlach at the Diecke Center

"We don't drive change. We have to follow it and keep up with it," Gerlach said. "We're always six months behind cutting edge because we have to be."

Tim Spangler is a reporter for the Medill News Service.

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