I doubt this issue a PureVision specific problem. With glasses or contacts your eyes don't have to work as hard and can tend to rely on them. In time without using glasses or contacts your eyes can sometimes return "slightly" to their previous good vision. I experience this all the time. Often people don't consult an eye doctor and sell prescribe their own glasses, getting ones that are to powerful because they can see even better using them. This only makes your eyes worse.