In a recent issue of AlertBox, Dr. Jakob Nielsen comments on differences and approaches of designing interfaces for accessibility.
The key difference between user interfaces for sighted users and blind users is not that between graphics and text; it’s the difference between 2-D and 1-D. Optimal usability for users with disabilities requires new approaches and new user interfaces.
One of the often discussed aspects when considering accessibility on the Web is the idea of delivering multiple versions of the same website, one purely for accessibility.
The Alertbox article comments and discusses the idea of a single-design-for-multiple-audiences approach, by commenting that often, due to time and costs, the two sites approach could result in the accessible version becoming out of sync from the main site.