The effects of LASIK are permanent or very long lasting in the majority of patients. We know this from many studies, and there are many patients who had LASIK done more than 10 years ago who maintain very low spectacle power.
Nevertheless, there are some people who do experience regression. The risk of regression is higher in some groups of people, such as those who had very high spectacle power to begin with, or those whose spectacle powers are still increasing.
I don't think it is possible to say in a particular patient, whether regression will occur, or when it will occur. If the risk of regression is judged to be high, then usually LASIK is not advised at the time.
For example, a person may be asked to wait until the spectacle power is more stable, perhaps in 6-12 months' time, before considering LASIK again.
Fluctuating vision could have several causes, and this needs to be treated in its own right before considering LASIK.
