Never use bitmap images of text. They are impossible for the blind to read. Low vision users can enlarge them, but persons who are legally or totally without any sight, can never read text images. Navigation is a challenge for blind and visually impaired users. Wherever possible, try to minimize the number of multiple hypertext links that appear in a single line of text.
Navigation is also difficult in web pages that feature multi-column displays.
These are a nightmare for the blind. Thus, when the browser displays a multi-column document, the screen reader reads each line, jumping from column to column until it reaches the end of the line. This makes it very difficult for the user to follow, since there is no logical construct for the screen reader to follow. Additionally, in every case, include keyboard equivalents for mouse commands. Lastly, the richness of the description of the document structure is the greatest friend of the blind user, particularly those who use Braille displays or print documents that must be translated to Braille.