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| "from what I understand, the minification caused by glasses is because
a larger portion of the external image is focused on the forva. This
is effect is reduced when the lens is closer to the eye ( such as a
contact )."
I know it has to do with vertex distance. If I hold my glasses away
from my face, things get blurrier and more minified. If I put on two
pairs of glasses, things are blurry due to overcorrection but then
holding both pairs away makes things tiny but clear much like looking
at binoculars at the wrong end. Contacts sit vitrually on the eye so
any minification is too neglectable to be detected. High myopes often
dont see 20/20 with glasses due to minification. I know this -10 lady
whos 20/25 with glasses and 20/20 with contacts. Not supprising.
"Reshaping the cornea under the flap moves the correction closer to the
lens than any contact lenses."
True but its a neglectable difference of a few dozen microns. Things
would be just a tiny bit more magnified but youd never notice that just
as youd never notice the minification with contacts.
"If you take into account the slightly increased cone density along
with the smaller size of the forva sometimes associated with axil
elongation, it is quite possible that better than 20/20 is more the
norm if the lasik is done perfectly."
If I understood correctly, axial enlongation stretches the retina so
actually theres LESS cone density as they are spread out due to the
stretched retina. This accounts for the fact very, very high myopes
usually have subpar corrected vision even with contacts. That and
having such a stretched retina results in thinning and degradation as
obviously retinas werent meant to be stretched like that. The problem
generally only starts at -10 and up where the stretching becomes too
extensive, too much stretching. The fact you could still see 20/20 with
a -6 pescription means you had fewer than average high order
aberrations and higher cone density, even with the slighly stretched
retina of yours. All high myopes of -6 and up that correct to 20/20
with glasses are more likley to get better than 20/20 with lasik for
some of the forementioned reasons.
"It is quite possible that the central field of vision used for things
like reading may be slightly reduced ( but probably less than someone
would notice moving from glasses to contacts ). Hardly what I would
consider a "poor field of vision"."
I notice a poor field of vision with plus glasses. It magnifies things
but at the expense of field. I get a close up but can see less of it at
once. Lasik would make a neglectable difference unlike glasses.
"My doctor had very detailed graphs of all his patients snellen results
at their 12 month follow up. They looked like basic bell curves.
Prior to lasik, I was a "perfect" -6.0 based on his wavefront
diagnosis. According to his data, with my prescription and the laser
he recommended, I had a 99% chance of being 20/40 or better, 94%
chance of being 20/20 or better, a 40% chance at 10/15. the curve fell
very rapidly from there, but I believe it was about 4% at 20/10."
Some doctors like to claim a 50-75% chance of 20/15 but that isnt
feastable for the average person. Select people may have that chance
for 20/15 if they end up plano or if not, they can achieve that with
glasses nonwithstanding a complication that results in loss of lines of
BCVA.
Getting 20/40 is easy, but not everyone is happy with that and they
usually get an enhancement or a thin pair of glasses. If you cant
correct better than that post-lasik its considered a complication and
loss of lines of BCVA. Any loss of vision in snellen or at night is
bad. I know someone who corrected to 20/15 with glasses but got "only"
20/15 with lasik and she noticed things werent quite as clear.
"He told me that going wavefront wouldn't give me better vision than
traditional lasik. For my prescription, he statistically had better
results from the non-wavefront B&L217a than any of the wavefront lasers
in his shop. Go figure!"
I guess considering you had few aberrations to begin with, there wasnt
anything to work with using wavefront. Both lasers would induce more
aberrations due to the flap and uneveness of the ablation and healing
response. Wavefront is used for those with a large amount of
aberrations. Some new aberrations are created while the old ones get
reduced. It will take years of refining to improve the lasers to remove
more aberrations while inducing less aberrations. Theres a good read on
polynominal HOAs. Search google for articles. I read that by the year
2010, theres expected to be a new breakthru in laser technology that
can supposedly give a 50% chance of 20/10 vision. Itll have to be seen
to be believed. Right now, a little less than 50% of people even end up
with 20/20 vision!
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