http://www.readingandwriting.ab.ca/judypool/irlen.htm#test The reason many people (including myself and Paul Scheele) turn to reading-enhancement techniques like PhotoReading is that reading the regular way is just too hard. It's not just that there's a lot to read... business or educational information overload... but that the act of reading itself is just too hard.
Irlen Syndrome effects between 12% and 14% of the population. (I'm austic, and almost 50% of us have it). The thing about Irlen is that there are ways to reduce the eye-strain from it while reading. This would make photoreading more enjoyable, less stressful. I paid for the Home Study course, and I'm good at photoreading, but I rarely do it because of the Irlen issues. (I'm good without practice for the same reason I have Irlen... about 50% of the autistic population has it, and while I am not a "natural," once I learned how to do it, it became a "Savant" skill, much the way I've always read three to five grades above my level in school. Don't take my unusual skill as an excuse not to Photoread).