Get two small, matched, low power magnifying lenses. Mount them with the lenses "pointing inward" as if they are "cross-eyed". I suspect that the angle of inward tilt would be the angle that would cause both lenses to be "pointing" at the same point at the lense's focal length. The lenses, of course, in the most simple contraption would be spaced eye pupil to eye pupil and mine seems to work best about 2 or three inches in front of my eyes. Good luck!