Renee,
I'm betting that's what the cause may be for me, too. There is just this small, annoying fold of skin over my right eye. When I raise my eyelids, the right side goes up but takes more effort. At a relaxed position, you can tell that my right eyelid has a slight sag and extra fold of skin to it.
The lack of strength in my arms is troubling. I'm finding it difficult to do things that should be easy (i.e. lift grand piano lids, plug things in to electrical wall outlets, fill my coffee cup from the coffee pot, etc.). It doesn't get better, only worse. The strength in my arms doesn't return - they just get a little weaker. With MG, I would expect to have periods of regaining strength after resting.