I would recommend doing a full relaxation exercise. Get the conscious mind entirely out of the equation and your concentration will be absolute. In the beginning it can be a little time consuming but after a few sessions like this your body will begin to associate deep relaxation to photoreading and getting into state will be much easier. As easy as the 3 to 1 method in fact.
You might also want to consider a meditative practice of some sort (or yoga, holosync, spring forest qigong, or something). I used to have an extremely active mind that made sleeping difficult. By incorporating some relaxation into your life the adrenaline and cortisol levels in your blood stream will drop. That kind of a biochemistry makes concentration extremely difficult and its exhausting. Just a suggestion.
