I believe that you want to relax your gaze to encompass both pages at the same time, allowing yourself to take in the edges and corners of the pages, the white spaces, and the text. The text will probably be a bit blurred at first. That's pretty normal, and is a function of where your plane of focus is (which will probably be out at infinity at first). Eventually, you might see both pages rather clearly (which is due to each eye focusing seperately and moving the two focal planes in from infinity to the page).
I have found that the Tangerine Technique is useful for expanding my gaze. When I place my awareness at the back spot on my head, my gaze seems to automatically open up.
