Patients often ask, well, what if I move my eye? I don't want to not see well, because I did something wrong, doc, what can I do to make sure that that doesn't happen? Well, rest assured, there's an eye tracker on the excimer laser and that eye tracker will follow the eye as it has it's small movements during the procedure. The changes that are made in the patient's eye with Lasik are permanent. We can see those changes years down the road. Now, we're not putting a brace on the patient's eye. In other words, eyes can change a little bit over time. If the vision changes significantly. However, patients can undergo the procedure again for a little fine tuning. Usually, that's not necessary, but it is available to patients if they feel the need.