I've had double vision for 9+ years. It's mostly been vertical, but occasionally changes to vertical + horizontal. The double vision always goes away if I close or cover one eye. Recently I've had some decrease in my double vision with being on prednisone and cyclosporine. In addition, the weakness in my arms and legs have decreased significantly. But the double vision still seems the most difficult to treat. I'm losing hope that I'll ever return to NO double vision.

It sounds like it'd be a good idea for you to be evaluated by a neuroophthalmologist. I hope that you're able to get some answers.
Cate