You can look into PhotoReading and Mental Photography. The ideas sound "scammy," but if you look at what's being said generally, it'll help you (centering your mind, entering the alpha state (you can even use brainwave entrainment until you can do it naturally), suppressing subvocalization (repeating the words in your mind), scanning the table of contents and pages of the book to get a "big picture" sense of what it's about, "activating" what you've read (after taking a nap) by summarizing it out loud, etc).
Also, you can try taking supplements that help with concentration and maintaining awareness. Things like (N-Acetyl) Semax (Amidate) + N-Acetyl Selank + PhenylPiracetam Hydrazide.
If you ask questions, keep your mind active, and engage in what you're reading (visualizing, questioning, etc as you go), then it becomes easier to pick up on things, keep the pace, and fly through it all without even noticing.
Moving your eyes faster is really basic and almost stupid, but the idea of keeping your eyes moving (to prevent backtracking and spacing out) makes sense.
Also, if you have the choice, then it's better to read from a crisp-screen-having tablet, such that you can adjust the font size, width, and spacing of what you're reading, and can have software automatically scroll through the text (and show just the right amount of text at a time, to allow you to digest quickly without having to move your eyes).