Hard to say, while not as extreme, I do cycle through 3 different eyeglass Rx's ... 4 if you include not needing glasses at all, throughout the week. And other than about 2 years ago, when my optic nerve was inflamed, all other appts have been fine. But I don't know if it's MS or allergies, the eye docs and neuro aren't real sure either, since neither can rule out the other.