These are repeated a few times over the period of one half hour to make sure your eye is immobile. A speculum is gently placed on your eye to ensure that your eye stays open while the surgeon performs the procedure. There is no discomfort, since the drops placed in your eye prior to the procedure will affect your eye until well after the procedure is completed. The technology varies from clinic to clinic. Depending on the equipment, the surgeon will then place a suction ring on your eye that will hold it steady for the entire procedure.
Some machines actually track and follow the pupil.
Rather than making cuts in the cornea, the PRK procedure uses an excimer laser to shape an area 5 to 9 millimeters in diameter on the surface of the eye. The major advantage of this procedure is that the integrity and the strength of the corneal dome is retained. Some patients see a dramatic improvement in their vision the first day. For others, vision may be blurry and fluctuate for several weeks to several months. Most patients return to normal activities in 1-3 days.