Keep lots of white space between columns of text.
People who are blind do not use mice or other pointing devices—a pointing device is of no use when you can't see where it's pointing. Therefore, you have to make sure that your documents are "keyboard friendly" as well as suitable for screen readers or Braille devices.
Remember: If a piece of information could be inaccessible to someone, always convey that information in a second format, and make sure that any information conveyed in an image or diagram is also available in text.
In addition, if your document has columns of text, make sure that you have a big gap of white space between each column. Some screen readers can read straight across the first row of each column rather than down a column at a time; a large gap between columns helps solve this problem. It will also make your document easier to read for everyone, especially people with low vision.
In the next two sections, there is some more advice on how to make your documents suitable for people who are blind.