The excimer laser is able to meticulously sculpt the corneal surface, altering the surface optical architecture to correct refractive errors. Such surgery is achieved with minimal mechanical and thermal effects upon the remaining corneal tissue. The excimer laser is based on the combination of two gases - a noble gas and halogen. Both of these are generally stable in their normal low energy state. When a high voltage electrical discharge is delivered into the laser cavity containing these gases, however, they combine to form a higher energy gas state compound. Upon the dissociation of this high energy compound, a photon of energy is released corresponding to the bond energy of the noble gas: halogen molecule(5,6). This wavelength of light energy is amplified in the laser system resulting in the production of a discrete high energy pulse of laser energy. The specific wavelength of an excimer laser depends on the gases utilized. Excimer lasers in current clinical use rely on argon and fluorine gas to emit a wavelength of 193 nanometers, thus falling in the UVC range of the light spectrum.