With most patients, the results are long-lasting. LASIK has been performed for approximately 10 years, and the general consensus is that it is a stable procedure. PRK has been performed for approximately 12 years, and appears to be a stable procedure. LASEK has been performed for about three years and also appears stable. Some patients, however, develop changes in the lens, called nuclear sclerosis, that can cause a shift in myopia. In this case, an enhancement can be performed although this may not be necessary. As with any surgery, there is always a risk/benefit ratio with respect to further procedures.