See a neurologist and rheumatologist as could be MS, fibromyalgia, or other systemic problem.
Have you been to an ear specialist--a neuro-otologist, also spelled neurotologist?
Had an ENG/VNG (electro- or videonystagmography, to look for abnormal eye movements)?
I'm not any kind of expert and have no medical training, but I wonder if the eye problem is a vestibular one? However, if you've seen neurologists, they surely would have considered that and referred you if necessary.
Migraines can cause all kinds of weird stuff. Since you are having headaches with the vision problem, that would seem to make sense, I guess.
Good luck...
Nancy T.
After the work up you've had I have no additional thoughts on the problem.
JCH III MD