PRK was the first excimer laser method used, it is a highly reliable technique, and it is especially preferred for patients with a thin cornea. Although it is not suitable for patients with very high refractive errors. It gives very good results in cases of thin corneas or low-degree myopia. During this process, the laser is applied directly to the cornea without lifting the membrane (flap) in the front part of the eye. For 2-3 days after this laser treatment there may be some pain,stinging and tearing may occur.