There are various eye surgeries that people with impaired vision can undergo in order to correct it. There is what they call as refractive eye surgery, which is an elective process with the intention to correct the usual eye disorders known as refractive errors like nearsightedness or myopia, farsightedness or hyperopia, and distorted vision or astigmatism. Laser refractive correction is one of the surgical techniques being done nowadays to correct refractive errors and is fast becoming the most technologically advanced technique available. 
In ophthalmology, laser surgery is hailed to be the most exhilarating progress. Unexpectedly, in spite of its abrupt fame there are merely twenty percent of ophthalmologists in America that are presently qualified in its operation.
The excimer laser was the first to be approved by the Food and Drug Administration on October 1995 for the correction of mild to moderate nearsightedness. The agency, along with the approval, also limited the utilization of the laser to eye practitioners skilled in laser refractive surgery and in the calibration and operation of the laser. The excimer laser has been permitted for utilization in a process known as photorefractive keratectomy or PRK and a process known as laser in situ Keratomileusis or LASIK.
Photorefractive keratectomy is an outpatient process commonly done using the local anesthetic eye drops. This kind of refractive surgery smoothly restructures the cornea by taking off the microscopic quantities of tissue, which can be observed under the microscopes such as clinical microscopes, from the external portion with a cool, computer-regulated ultraviolet beam of light. The beam is so accurate it can slice notches in a strand of human hair and not breaking it, and every pulse can take away thirty-nine millionths of a tissue inch in twelve billionths in one second. The process itself gets merely several minutes, and patients are commonly reverse to everyday routines from one to three days. The eye of the patient is gauged to ascertain the level of visual turmoil, and a diagram of the external portion of the eye is built prior to the start of the process as examined by means of microscopy using the clinical microscopes. The needed corneal variation is gauged according to this knowledge, and then recorded into the computer connected to the laser. There is only limited quantity of laser systems that has been allowed by FDA to correct different refractive errors in photorefractive keratectomy and laser in situ Keratomileusis.
Clinical researches illustrated that approximately five percent of patients continued to at all times wear eyeglasses after photorefractive keratectomy for distance, and equal to fifteen percent have to wear eyeglasses sporadically like when driving as patients eyes were checked using the clinical microscopes. Furthermore, as normal course of healing procedure, a number of patients endured mild corneal haze after surgical operation. The haze seemed to influence little or zero effect on final sight, and could only be observed by an eye doctor using a microscope like the clinical microscopes. Several patients endured brightness and halos surrounding the lights. Nevertheless, such eye conditions vanished or lessened in majority of the patients in six months time. Approximately five percent of patients though best-corrected sight with no corrective lenses was somewhat worse after undertaking surgical operation as compared with their situations prior to the surgery. Such findings were ascertained through examination done to the patients with the aid of microscopy using some clinical microscopes. Also, due to these findings, FDA and Federal Trade Commission warned about claims that would mislead or misinformed the public.