I just discovered a reading test based on the concept of a 'tachistoscope' ...a device which flashes text at a certain rate to measure perception.

At this site, you can choose a file of text to read and the rate at which it is projected, as well as the font and size. They have a few sample files, and I was up 220 WPM and still following "The Detective" just fine.

(Note..the program is JAVA based, so you would need it installed to run the test.)