As an example, a soft walled balloon will blow up to a different size than a firm walled balloon under equal pressure. We are ablating variable human tissue, not a piece of plastic. Since the epithelium is the very front layer of all the optical elements of the eye, it's contribution to the final end result is not insignificant. In summary, as fascinating as wavefront analysis might sound, and despite the marketing hype that is often accompanied with this process, the clinically important problems in the visual system are limited to the anterior surface of the cornea, which is now well documented with current corneal topography technologies, without the need for expensive wavefront analysis that contributes nothing. The problems with the visual system can be detected with simple topography and treated directly with a scanning spot laser.
Corneal topography can demonstrate decentrations and other irregularities.
A broad beam laser of 6 mm is incapable of accommodating focused ablations of the cornea to compensate for minor corneal abnormalities that may only be in a 2 mm area. A smaller beam, such as the LSX beam of less than 1mm diameter, can be more easily programmed to take care of these small irregularities. Wavefront technologies are interesting, experimental, and are unlikely, if we really take everything into perspective, to lead to final results any better than results produced by truly looking at all factors known in today's world. To date, some experimental patients have indeed been done using wavefront guided lasers - and actual results still do not validate any superiority in final visual function.