Hi jcitron,
My experience has been exactly yours.
I used to be short sighted, and I know you go more long sighted as you grow older. This has happened, and I can even drive without my specs now. However, I used to be able to read the smallest print without glasses, but no more. I have lost the ability to read small print catastrophically in a very short time.
I believe this coincided with starting Mirapex 18 months ago. I have a PD friend who suffered exactly the same on Mirapex and changed to cabergoline. You don't say what meds you are on, but what agonist are you taking?
Ron