Victor Tsaran, an engineer and Program Manager for Accessibility at Yahoo!, has put together a 27-minute video introducing screen readers and how they interact with web pages.
This is a very interesting insight into how vision-impaired people use the web and Victor makes several points that should of interest to web developers. He emphasises the need to correctly mark up your content and the importance of headings and lists. Headings can be used to navigate around a page to get an overview of the content without having to tab through all the links or read the majority of the content. And presenting your links as lists is also very important, especially if there are very many links, because lists of links can be skipped over, again avoiding having to tab repeatedly to get to where you want.
If viewing the video sparks your interest in how vision-impaired people interact with websites and would like to explore the issue further, you might consider downloading and installing a free screenreader to see how your own site stacks up.
So why should a vision-impaired person's experience matter to web developers? Well, Blind Citizens Australia's 2004 report, Clear Insight: The Economic Impact and Cost of Vision Loss in Australia, indicates that about 2.5% of Australians are vision impaired in both eyes with the figure to increase by 73% over the next two decades.
That might not seem like such a large number of people, but as I read on a mailing list recently, you shouldn't think in terms of the 97.5% of people who don't suffer from this problem, but rather think about that 2.5% and how that equates to numbers visiting your site. If your site gets 1000 visitors a month, that's 25 people who may have a less than ideal experience if your site is inacessible. Would you really be happy with that number of people having a less than ideal experience?
There's no need to be put off looking into how to make your sites more accessible either for fear of thinking that it's too hard. Accessites provides some easy to implement tips on Practical, Entry-Level Web Accessibility.