I recently read a fascinating survey of 1000 blind and visually impaired internet users. It's a long article but is largely graphs and data tables – so is easily consumed. If you want the short version, check out the comments and conclusion.
The most surprising parts for me were;
- Websites that auto-play music (MySpace most notably) are extremely difficult because the sound makes it hard for the user to listen to screen readers. Further, the flash music player is usually inaccessible for screen reader users, so the music can not be stopped and the page is completely unusable.
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