Catie,

Whenever I have a good spell, I wonder if I'm imagining things!

My understanding is that the antibodies that cause MG often don't show up on the tests of a patient whose MG is purely ocular. Wikipedia's Ocular Myasthenia article says "Autoantibodies against ACh receptors are detectable in 70-90% of patients with generalized MG, but only 50% in ocular myasthenia." I've read the same thing elsewhere.

Also there are at least two known antibodies that can cause MG, and there are probably more, since some MG patients don't test positive for either. Google "seronegative myasthenia gravis." In addition, there's a congenital form of MG in which there are no antibodies at all. It's called "Congenital Myasthenia Syndrome," and its symptoms are sometimes not recognized until adulthood. See http://www.mayoclinic.org/myasthenia-gravis/.