LASIK surgery permanently changes the curvature of the cornea to correct for your prescription. The vision is stable once the healing has completed. I have been performing LASIK since 1991, and I have had patients who stayed 20/20 for over 3 decades ! There are a few important facts that make people question how permanent LASIK truly is...

During the first few months following LASIK, the prescription can shift somewhat due to the natural healing processes. The body does not know you are having LASIK to deliberately change your prescription, and if you have a high prescription, nearsightedness, farsightedness or astigmatism, the prescription can shift say 10% back toward the original prescription and eye shape. Patients can then elect to have an enhancement procedure, whereby the original flap is re-lifted with special techniques and additional laser pulses added to compensate for the healing of the eye. It is rare for the prescription to ever change again.

The second reason that a prescription can change is the natural aging or growth of the eye. That is, if you have LASIK at 18 years of age for -4.00 diopters, but you were genetically going to be -5.00 diopters at 25 years of age, then at 25 years of age you will be -1.00D. LASIK does not stop the normal growth of the eye. Typically I account for such healing and it is built into my planning to "over-treat" younger patients. This is routine in the military programs and does not cause any issues but ensures excellent vision for decades.

Similarly, when you develop cataracts later in life, the prescription often changes and this would be independent of whether or not you had LASIK.

One more important note, after the age of 40, the internal focusing muscles begin to weaken and typically between 40-50 years, every normally sighted person requires reading glasses. LASIK makes nearsighted and astigmatic patients normally sighted, so they too will require readers. Farsighted patients usually require readers at a younger age. This change is called Presbyopia and occurs whether someone has LASIK or not.