When I started with Photoreading I searched for ways to see for myself whether or not it could be done.
Concerning the question whether or not words enter my mind even though I am not consciously looking at them (not in focus) I thought about words or parts of words, i.e. "where are words starting with an a" or "where is the word "brain" and then gaze at a page, very unfocused. My eyes would quickly be drawn to those words. That was convincing enough for me concerning the pure mechanics of whether or not letters enter the brain. Actually, the idea for this sort of self-test came after an even simpler excercise which I got from somewhere from the LS materials: If you walk some place tell yourself to find all things red, or all things round ... whatever. All of a sudden you find tons of objects around you with that particular characteristic + shades and variations!