Hey, I have double vision pretty constantly. Can see but to read or the like forget it. I wear prisms in my glasses. I suggest that you find a neuro opthomologist. This is a person who is very proficient in the ways that neuro disorders effects the eye and how to best treat it. Missy is right though, it has to be pretty consistant to use the prisms. A few years back, when mine started, the neuro optho said I would need 10 diff pairs of glasses to use---the degree of dv was not constant and so would constantly need to change them. Now I use mine all the time. Need new ones if I get around to getting them. Hope this helps