The S2 is the newest addition to the laser surgery center at the Buzard Eye Institute. It is an upgrade to the previous VISX Star Excimer Laser System that allows for extremely smooth surfaces and greater accuracy. The excimer laser produces ultraviolet light which has the ability to remove corneal tissue almost without disturbing surrounding tissue. This ultraviolet light can then be shaped with lenses and controlled with a computer to actually create a corrective lens on the surface of the cornea. More nearsightedness would remove more corneal tissue while a small correction would require only a small amount of corneal tissue removal.
Corneal tissue is removed simply by exposing tissue to the ultraviolet light.
The longer the cornea is exposed to the beam of light, the more tissue is removed. Astigmatism can be corrected by adding an expanding slit to this arrangement, thus exposing one meridian of the cornea to more ultraviolet light than the opposing meridian, a feature found only on the VISX laser and not on the Summit. Last Updated on August 28, 2001.