Beagle, I would think a regular monocle would be difficult since one always has to squint or do whatever to keep it in place, though it might work.
A hand-held monocular could be an option as well. The hand held monoculars typically have considerable magnification though, and function in essence as a telephoto lens. You would need to find one with as little magnification as possible. Perhaps someone makes a 2x? I don't recall if the 4x is the smallest magnification power. They are worn around the neck for easy access, and are quite commonly used by those who are severely visually impaired (as in legally blind).