For people born with normal vision, light passes through the cornea and focuses directly on the retina at the rear of the eye, producing clear vision.
If you wear contact lenses or glasses, you're physically unable to focus light on your retina. You have a vision error, typically genetically determined.
There are three primary vision errors, each the result of an eye shape that differs specifically from that of a normal eye. These errors include nearsightedness (myopia), farsightedness (hyperopia), and astigmatism.
A fourth error, called presbyopia, causes a loss of reading vision, for which a laser vision correction technique, called monovision, can compensate.
A farsighted, or hyperopic, eye is shorter in the cross section than a normal eye, causing light to focus virtually behind the retina, blurring your vision (see animation below).
Dr. Hyver can use either LASIK or PRK for farsightedness correction in his San Francisco, San Jose or Walnut Creek offices. He does so by applying the laser to slightly steepen your cornea, redirecting the light's focal point from virtually behind to directly onto your retina.
The following animation illustrates farsightedness:
