How PRK Works

The laser used in photorefractive keratectomy is called an excimer laser. It emits a specific wavelength of far-ultraviolet light energy that vaporizes fractional layers of cells, leaving a very smooth surface. By carefully sculpting the shape of the outer layer of the cornea, this laser -- a "cool" laser that does not produce heat -- creates an optimal surface layer for the eye's lens. For nearsighted patients, the laser slightly flattens the top of the cornea. For farsighted people, PRK surgery yields a slightly steeper cornea. In patients with astigmatism, the laser smooths out irregularities. The equipment your surgeon uses includes a corneal topographer, an instrument that can perform the precise measurements and calculations needed to map your cornea and the desired correction.