The CO 2 skin resurfacing laser system produces an intense beam of light of a specific, known wavelength. There are two types of lasers produce light that is well absorbed by the upper to middle layers of the skin, light produced from carbon dioxide gas (CO 2 ) and light produced from a crystal made of erbium, yttrium, aluminum, and garnet (Er:YAG). Combination lasers are also commercially available. Before the procedure begins, medication is often given to relax the patient and reduce pain. For small areas, local topical anesthetics are often used to numb the area to be treated. Alternatively, for large areas, nerve block-type anesthesia is used. During the procedure, the patient lies on his or her back on the surgical table, eyes covered to protect them from the laser light. Laser passes are performed over the area being treated, utilizing computer control of the laser for precise results. The laser skin resurfacing is used on the face, as elsewhere the healing process may be so slow as to result in scarring.