Christopher Zoettl wrote:

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you don't have the best you can get, either the corrective lens is too
strong or it isn't strong enough.

In this case (for myopia), I would prefer a lens that isn't quite strong
enough, since this at least makes reading more comfortable. If it's too
much minus, that doesn't help for any task.
--
Robert T. Kopp
http://analytic.tripod.com

Someone here really messed up the forums by providing some fault
information. Obviously the people in the know are quite frustrate
it and I'm having trouble comprehending when there's exces
information about metaphors and semantics.

I'll start by trying to answer the actual question

20/20 was determined when the eye is at it's relaxed state, starin
into the distance that an object should focus to a point on the bac
of the eye. This optimal distance was decided at 20 feet. So
measurement of how clear or unclear a person's visual acuity is no
measured by 20/20. You see at 20 feet what you SHOULD be seeing a
20 feet.

Some people's eyes are capable of seeing things at 20 feet what th
norm should be seeing at 15 feet. So you see better!.. and som
people eyes are not as good because of one reason or another and the
see 20/30.. so you see something sharp at 20 feet when others see i
at 30 feet.

A lens put in front of your eye, being contact lens or eyeglasses wil
"BEND" the light accordingly so that the light focuses where i
should. With people who are far sighted, the image focuses past th
point where it should. People who are near sighted, the imag
focuses before the point where it should. LENSES, help push thi
focus point to where it should be for the best vision possible

Some people can deal with 20/30 sight because most of their lifestyl
maybe more critical for near vision .. and less for far vision. Tha
is why some people don't mind it even though it's less than optimal.

Optometrists or Ophthalmologists will try to correct for 20/20 .. i
you can see better than that, then they will correct for it.. bu
most people don't need it. Even if you put a higher prescription i
front of someone's eye will not make it sharper for them.. it wil
most likely make their eyes more tired by the end of the day.

Hopefully that explains things

FURTHERMORE, Chris a plus lens... +2.00D does not make things smaller
A +2.00 lens is basically a magnifying lens and therefore will mak
objects look larger.

Dear Chris,

I see you have the same book that I do -- concerning Kepler's
first "assumption" the an un-desired refractive state of the
living eye was an "error", and that analysis carried forward
through the years to the "Gullistrand" paradigm.

And excellent analysis -- of an assumption.

Until you realize that you are analizing your false (but honest)
assumption about the living eye -- not much preventive-progress
can be made.

If you "accept" that the living eye must be a dynamic system,
and build a "working model" of it -- then the "picture" becomes
profoundly different.

This type of "change" is called a "paradigm" shift or "change"
described by Thomas Kuhn, in "The Structure of Scientific Revolutions".

When the "paradigm" changes, then even the word we use
to describe the living eye must change also -- which
is why I insist on describing the living eye has having
"refractive states" -- and completely normal -- as least
from -1 to +2 diopters.

All these refractive refractive states are called "ametropia"
as Dom insists.

Thus the effect of the "Kepler" assumption is to make
all natural and living eyes "defective" because of
our assumptions.

And that does include the Gullistrand model.

Do not get me wrong. It is nice to calculate
curvature to 6 significant figures -- but
it does not mean very much because
it can not possibly repesent the proven
behavior of the primate eye.

Further the "accommodation" model -- could never
"work", and could NEVER be made to work either.

The total power of the eye is controled by micro-blur
sensed at the surface of the retina, and the "sharp"
image is maintained by continuous feed-back from
retina to lens.

But that is why you can not specifiy "'length" and
should stick to what is measured, i.e., refractive
state, and not extrapolate a state into a "length".

Best,

Otis





But what if the cornea has to much refraction. I mean a
Gullstrand-Cornea has a refraction of 43.05 dpt, what if an eye has a
refraction of 45 dpt? Then no matter if the eye were living or a box
camera, the light beams would be to short, because the cornea makes a
static refractive error -

otisbrown[at]pa.net schrieb:
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the eye might not be a box camera, and the lens of the eye may be able
to adapt.
But what if the cornea has to much refraction. I mean a
Gullstrand-Cornea has a refraction of 43.05 dpt, what if an eye has a
refraction of 45 dpt? Then no matter if the eye were living or a box
camera, the light beams would be to short, because the cornea makes a
static refractive error -http://www.usherbrooke.ca/ophtalmologie/images/Predoc/Erreurs_refraction/myopie.jpg

What purpose would resolve for me by looking 10% of then time to infinity?
If I have a +2 lens infront of me this would resolve only in an angular
magnification of 0.5x . Which means everything would get smaller. How
should this be helping the eye?

Best regards

Chris

acemanvx[at]yahoo.com schrieb:
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I also disagree on a lot of what you said. But I respect your opinion.

Best regards,

Christopher Zoettl

not to mention ineffective also.

Dear Mike,

Thanks, it is metaphor.

Given the "quality" of the post here -- I agree, please prescribe
for the sharpest vision possible.

That is the only thing that you can do. Any preventive
work would truly be impossible.

Best,

Otis

On 3 Feb 2006 08:34:08 -0800, otisbrown[at]pa.net wrote:

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Dear Christopher,

Please disregard Otis. He is not in the medical profession nor in any
position to give medical advice.

Thank you.

Allen

<otisbrown[at]pa.net> wrote

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If you're going to lecture us on "sematics" as well as medicine and science,
please check your spelling.

-MT

otisbrown[at]pa.net wrote:

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legal disclaimer? just in case it's quackery?

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Scientific common sense? I didn't know that science
involved common sense. I thought common sense was
what you used to make decisions in the absence of
objective facts or insufficient information.

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Probably because it's not based on science and you have
no common sense?

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Bzzzt, no legal out here. You're now saying that you're only
suggesting a personal choice and not addressing a medical
issue? Sounds like you're back peddaling.

-Quick