If you have a child struggling with reading you might try printing text in different fonts, larger fonts, and increasing the spacing between lines.
I recently found out I have a relative that can not read, in certain fonts. He was fine for the first sixty years of his life, but something happened in the last couple years and he fonts with little curvy things have become impossible for him to read.
I wonder if at some point we'll be able to buy books in easy to read fonts? I would think publishers would take note of studies like this and try to maximize their sales by using fonts which more people can read.