> > Did you not see a phoropter hanging in your doctor's office, and has it
> > really been that long ago that you've had a refraction for eyeglasses?

> theoretically wavefront could make a slight improvement in visual
> acuity. the problem is, with wavefront eyeglasses on, if the eye moves
> off axis in any direction then the wavefront correction is off center.
> also, with wavefront contacts on, if the lenses move or turn (they do)
> then the corrections becomes off center. in a nutshell, wavefront
> lenses won't work. and practically speaking wavefront LASIK hasn't
> proven to be any better than standard LASIK.

> On 5/3/06 4:35 AM, in article
> 1146656113.076384.256840[at]y43g...oglegroups.com, "Dr. Leukoma"
> <drg[at]leukoma.com> wrote:
> > Did you not see a phoropter hanging in your doctor's office, and has it
> > really been that long ago that you've had a refraction for eyeglasses?
> > > Traditional refraction does a perfectly fine job of correcting lower
> > aberrations of sphere and cylinder, which have large amplitudes and are
> > symmetrical with respect to the visual axis. What's left over are
> > termed "higher order aberrations." Most people have low amounts of
> > higher order aberrations. Refractive surgery, however, increases the
> > magnitude of higher order aberrations.
> > > The human eye is optically limited to about 20/15 resolution. The
> > neural limitations are about 20/6. There are tradeoffs of having
> > vision corrected to this level. Wavefront generated contact lenses and
> > eyeglasses are indeed possible, but are impractical at this point in
> > time because of problems of tracking and registration.
> > > However, simple RGP contact lenses probably do the best job of
> > correcting higher order aberrations, especially those that are induced
> > by LASIK.
> > > DrG
> > Not being a vision professional, I have presumed that wavefront correction
> is merely a new technique for what, in optics, has been called figuring.
> Figuring for lenses and mirrors has been carried out by a number of
> techniques for centuries. Knife edge testing is just one of these
> techniques.
> To me, the term "wavefront" implies some form of interferometry. I do not
> know how such interferometry is carried out in optometric practice. How is
> the reference wavefront, against which wavefront error is measured,
> obtained. In principle the wavefront of an ingoing beam gets focussed onto
> and then scattered off of the retina to provide an outgoing wavefront
> through the eye's optical system. The two wavefronts can then be compared to
> measure the error. Is that the way it is done?
> Bill
> -- Ferme le Bush

> Did you not see a phoropter hanging in your doctor's office, and has it
> really been that long ago that you've had a refraction for eyeglasses?
> Traditional refraction does a perfectly fine job of correcting lower
> aberrations of sphere and cylinder, which have large amplitudes and are
> symmetrical with respect to the visual axis. What's left over are
> termed "higher order aberrations." Most people have low amounts of
> higher order aberrations. Refractive surgery, however, increases the
> magnitude of higher order aberrations.
> The human eye is optically limited to about 20/15 resolution. The
> neural limitations are about 20/6. There are tradeoffs of having
> vision corrected to this level. Wavefront generated contact lenses and
> eyeglasses are indeed possible, but are impractical at this point in
> time because of problems of tracking and registration.
> However, simple RGP contact lenses probably do the best job of
> correcting higher order aberrations, especially those that are induced
> by LASIK.
> DrG
Not being a vision professional, I have presumed that wavefront correction