Well, there are two different types of laser vision correction that are commonly performed. One is called Lasik, and that’s the one that is most commonly performed, and the other one is known as PRK. In my practice approximately 80% of patients receive Lasik, and 20% receive PRK. They are both excellent procedures, and both provide the same excellent stable results. The difference is that Lasik is performed under a corneal flap. So if you think of the cornea, which is the window of the eye, as a book of, let’s say, 500 pages thick, what we’re doing in Lasik, we’re actually in the first step opening the book to page 100 and creating a hinge in the cornea. In the second step of Lasik we’ll remove some pages of the book with a laser, one of these Excimer lasers that we have, to fix the vision and to resculpt the cornea. We then put the flap back down, and that is the end of the Lasik procedure. The PRK procedure for the same patient would still remove the same number of pages of the book, let’s say, 50 pages. However, it’s a more superficial procedure, and it’s done on the surface of the cornea. So there’s no flap created. We’re going to remove the same 50 pages, but it’s going to be pages zero to 50 instead of pages 100 to 150. Therefore, it’s a more superficial procedure, and it works better in patients who have thinner corneas and not enough tissue for us to do Lasik.