if you're seeing double images with your glasses on, remove them immediately, they're probably not made for your specific eyes which would cause vision problems to worsen
There is a chance of optical illusion if you are new to use spectacles. Next is if your eye defect and the power are mismatched you may see double images.
It sounds like what happened to my husband once. He wears no line tri-focal glasses. It turned out the lenses were made incorrectly and at the wrong strength.
