Do these symptoms sound like Polymyositis? After exercise or exertion, I feel these symptoms: dysphagia, blurred vision and have had double vision; muscle weakness in specific muscles, like shoulders, lower back, hands (those muscles that are being exercised or where there is repetition of movement); after l-1/2 hours I feel a general weakness; I also become confused and find it difficult to concentrate or do tasks, like counting change; rest. and better yet sleep is restorative. I have noticed a fine rash on my right eyelid, recently. The symptoms occur everyday now as a year ago they only appeared periodically.

Polymyositis wouldn't be the first thing I would think of. The symptoms you describe do sound significant and should be evaluated by a neurologist. Good Luck with this...