How fast do prisms work? my doc can't figure out why i see ghost images in each eye (separately) worn it for 10 min and hasn't change anything?

Right away: why do you need prism at your age? What is the cause of it? Did you see an ophthalmologist? If not pls consult an ophthalmologist. If you see ghost images out of each eye separately this is not muscle related. They may need to check your refraction and topography of your eye. I could not give you more info without more detail. The prism is more for double vision with both eyes together.