I would like to correct a couple of your statements, SIM52.
First, Mestinon kicks in after about 30 minutes. Two hours after that it wears off. So there really only is a matter of two hours of use.
Also, MG has absolutely nothing to do with the brain. No matter of plasticity or adapting of the brain will alter our weak muscles enough to refocus them. Mestinon is also not normally the best drug to address double vision.
One can't "force" the eye muscles to become strong enough so that the left and right eye muscles focus equally. Overdosing with Mestinon is not a smart thing, either. Your eyes could be "sore" because the muscles are being overdosed. Just as muscles without enough acetylcholine can twitch, cramp, or spasm, the same thing happens with too much of it.
Not everyone with MG is the same. Some people can handle a higher dose of Mestinon, or take it more often, but others can't.
Jane is pretty much a newbie, and is not definitively diagnosed. She needs the most accurate information she can have. Also, it is always best to consult with a neurologist before making any drug changes.
Well, that's more than two things!
I appreciate your viewpoints, but we do need to be as accurate as possible in relaying them. Thanks.
Annie