Creating Accessible Images
http://www.webaim.org/techniques/images/

WebAIM
2003

Abstract:

Some people think that graphics are bad for accessibility. The truth is that graphics can be of great benefit to the accessibility of a Web page by providing illustrations, icons, animations, or other visual cues that aid comprehension for sighted individuals. Too often we forget that when we design for people with disabilities, we are not designing only for the blind. We must consider disabilities of all types. Graphics can be especially useful to individuals with certain reading disabilities, learning disabilities, attention deficit disorders, or cognitive disabilities.