PubMed or similar databases may help you find researchers who are active in this field, although you'd have to choose the search terms carefully. I had some luck with terms like [reading computer "visual processing"] etc. A lot of what I came across was either fairly technical neuroscience stuff or occupational health stuff (e.g. eyestrain, fatigue), but some of that may be what you're looking for.
This book might be useful for background and to give you an idea of who was works in this field (ten years ago, anyway):
van Oostendorp, H., and de Mul, S. (Eds.) (1996), Cognitive aspects of electronic text processing. Norwood, N.J.: Ablex.
Paul Muter at U Toronto, who wrote a chapter of the above book, seems to do work along these lines (possibly part-time) and could probably put you in touch with interested students or colleagues; here's his webpage:
http://www.psych.utoronto.ca/~muter/ His publication list is probably a good beginning bibliography, too.
Companies that produce assistive technology for blind and dyslexic people are another potential source of information - the two big companies that come to mind are Kurzweil and Freedom Scientific. Again, these companies would have a niche focus, but may be able to put you in touch with R&D people who are familiar with the broader literature and could probably give you the "unviersal design" and accessibility perspective.