One of the main criteria for undergoing LASIK is that your eyes have stopped growing, which is usually not until at least age 18. Another is that your lens prescription needs to be stable, meaning unchanged, for at least one year. Astigmatism can continue to change (get better or worse) until around age 25.
Having LASIK or another refractive surgery before the eyes are done growing or before vision is stable can lead to vision regression. This is when vision is corrected for a time but then gets worse again because the original reason for the refractive error is still getting worse.