I know it's not what you asked, and I'm sure, given your situation, that you've already investigated your options, but you might take another pass at elevating your monitor.

My eyesight happens to be OK, but I overwork my eyes in a similiar manner - I crank the size down until I have a hard time reading it. I've found that having my monitors up higher encourages me to sit with the best possible posture. YMMV. Good luck.