The problem with the Prednisolone is that it takes a little while to work. A couple of years ago, I was having so many problems because of my inability to focus that it was affecting my work (I'm a legal secretary). My consultant finally put me on Prednisolone, increasing 5mg every week. It took me to 50mg to get my normal eyesight back (together with the Mestinon as well).
When I have previously had problems with Myasthenia (having been tentatively diagnosed when I was 15 and now being 34), very often the Mestinon doesn't seem to help a great deal. My symptoms have primarily been not drooping eyelids, but rather the lack of ability to focus, with no eyelid problems to be seen. When it is like this, very often I find it helpful to make sure I am not squinting at any point.
One of the most useful pieces of information I was given was by a nurse when I was leaving hospital on the one occasion that I had to be hospitalised due to a crisis. She told me to make sure that I wear my sunglasses in the sun. Very often I have found my symptoms to flare up in the summer and I am convinced this is because the eye muscles are being used to squint against the sun. It does help to make sure the eyes are not under any strain, so when I am having problems, reading is definitely off the menu, so that the muscles are relaxed. I have to say my eyes are more sensitive to light and wind for instance then previously.
I'm not a fan of Mestinon myself but I know there are times that I have to take it. The side effects are never pleasant, and when you have had cramps from taking Mestinon on an empty stomach, you don't do it again! Very often I find the Mestinon causes spasming of the muscles of the eyelid.
Hope this makes sense!