As a blind person myself, I have encountered some difficulties making pretty slide presentations using the usual Powerpoint/keynote tools. Although a visual impaired user can read and interact with these, and most try to do that, simple textual markup and well crafted templates can be far more effective. Developers and power users are specially at home in this regard. Some tools that can be used for easily producing slideshows in a accessible way:
- S5 and Slidy allow you to create accessible presentations using simple HTML markup. These are not only totally accessible to create (on can do that in notepad) but also very accessible for the visual impaired reader, as they can be viewed in a browser with a screen reader, as any other web page. SlideJS and others, although more complex, are options to consider too.
- Pandoc is a universal document converter. You can use this to write slideshows in markdown and convert them to S5 or Slidy presentations, which is far more efficient than writing HTML by hand.
- If using LaTeX, the Beamer package can be used to create pretty PDF presentations. Although the PDF output is less accessible for a screen reader user (comparing to HTML), it is a very nice option, specially in academic contexts or stuff that requires complex math formulas.
Hope this is useful for someone.