Hi Dave - - Welcome!

I think you know that MG does what it wants...when it wants. That having been said, you're probably right about the infection and marathon stresses combining to let the beast out of it's cage!

Anyway, I have never heard of THC helping double vision. And I would suspect that your first best option is Mestinon and total (as much as possible), boring rest and sleep for a couple of weeks at least. Maybe you'll get lucky and your body will reset. But it won't even think aout it if you continue to stress it with even normal activity.

RE: the pred - - it wouldn't be my first choice - but that's really up to you and your doc.

Good luck!