The eye is a very complex optical system. In its most simple form, the eye is called emmetropic. The term emmetropic means that you have no need for glasses and all things are in good focus.
Many people do have a need for glasses and they are called either myopic (nearsighted) or hyperopic (farsighted). Myopia and hyperopia are simple low order optical problems that can be corrected with lenses that are essentially spherical in shape.
The next more complicated optical problem is astigmatism. We sometimes describe astigmatism to our patients as a football shape curvature to the eye. In other words, instead of being shaped like a sphere or basketball, the astigmatic eye is shaped more like a cylinder or football.
Myopia, hyperopia, and astigmatism are all relatively simple, regular and predictable and can be easily corrected with routine glasses. However, there are higher order optical errors which can occur in the shape of your eye that are much more complex, irregular, and difficult to predict.
This complexity makes them significantly more difficult to correct with ordinary glasses. In cases of high order optical errors, the eye takes an irregular warped shape somewhere on the corneal surface.
How wavefront is used in LASIK eye surgery
In recent years, we have learned to use complex mathematical models to evaluate and treat higher order optical errors with LASIK eye surgery. The most advanced LASIK systems, like the Visx Star S4 IR™ system that we use, can measure and treat significant amounts of irregular astigmatism and other higher order optical errors.
Wavefront technology uses a type of mathematics that has been used for years by astronomers to correct for unusual or unpredictable optical systems. In the case of astronomy, scientists had to be able to visually correct for the difficult optical effects caused by atmospheres.
This same type of mathematics was then applied to the miniature world of the eye. We use a system called Customvue™ which measures the higher order optical errors using the AMO Wavescan Wavefront™ System and applies those measurements to the laser treatment during your LASIK eye surgery.
In addition, this system applies an aspherical treatment to the correction of your nearsightedness, which is believed to give superior optics overall. The Wavescan itself generates a precise optical measurement of your eye which is unique to you, like a “fingerprint” of your eye. This advanced technology allows us to generate superior optics customized to your eye in ways that were never possible before with older LASIK systems.
It is the precision of the AMO Wavescan Wavefront™ System coupled with the precision and safety of the Intralase™ FS Laser that makes up the advanced customized iLasik treatment that we use exclusively on all of our LASIK eye surgery patients. It’s the only way that we recommend LASIK in our practice.