What do they call this process...???...

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What do they call this process...???...

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LEESA...

Posted: Sat Oct 24, 2009 11:48 pm

Guest

Is there a name of the process where an optician can figure out the
prescription of a pair of glasses?

Is this hard to do? Can any optician do it and most importantly, can
it be done with precision and accuracy?

Thanks in advance

LEESA (I)

Otis...

Posted: Sun Oct 25, 2009 3:46 am

Guest

Dear Leesa,

Subject: Methods of measurement.

Re: Using a Snellen and Trial-lens kit.

No, it is not difficult to determine the refractive STATE of the eye.

You simply need a trial-lens kit and a Snellen to do it.

The instrument used in an ODs office is an "enhanced" trial lens kit.

But the process is to find a lens that "sharpens" your vision to your
satisfaction.

Enjoy,

On Oct 25, 5:48 am, LEESA <taylorlee... at (no spam) gmail.com> wrote:
[quote]Is there a name of the process where an optician can figure out the
prescription of a pair of glasses?

Is this hard to do? Can any optician do it and most importantly, can
it be done with precision and accuracy?

Thanks in advance

LEESA (I)[/quote]

Neil Brooks...

Posted: Sun Oct 25, 2009 4:43 am

Guest

On Oct 25, 3:48 am, LEESA <taylorlee... at (no spam) gmail.com> wrote:
[quote]Is there a name of the process where an optician can figure out the
prescription of a pair of glasses?
[/quote]
Neutralizing the lens

[quote]Is this hard to do? Can any optician do it and most importantly, can
it be done with precision and accuracy?
[/quote]
It's pretty standard.

Just like checking tire pressures, though, it depends on an accurate
instrument, properly used. Also, the more complex the prescription,
the more margin of error.

http://www.opticiansfriend.com/main/2006/01/21/how-to-neutralize-a-pair-of-spectacles/

Otis...

Posted: Sun Oct 25, 2009 5:08 am

Guest

Dear Leesa,

The instrument is called a "Lenonometer" (Sp?)

You simply place the "un-known" lens in the instrument and
"neutralize" the lens.

With a "Spherical" lens the results are generally to 1/4 diopters.

With a more complex (Cyl.) the results are less accurate -- but can be
made.

Enjoy,

On Oct 25, 5:48 am, LEESA <taylorlee... at (no spam) gmail.com> wrote:
[quote]Is there a name of the process where an optician can figure out the
prescription of a pair of glasses?

Is this hard to do? Can any optician do it and most importantly, can
it be done with precision and accuracy?

Thanks in advance

LEESA (I)[/quote]

Otis...

Posted: Sun Oct 25, 2009 5:10 am

Guest

Here is a more detailed description of this Lensometer:

http://vision.about.com/od/eyeexaminations/ig/Eye-Exam-Equipment/lensometer..htm

Enjoy,

On Oct 25, 11:08 am, Otis <otisbr... at (no spam) embarqmail.com> wrote:
[quote]Dear Leesa,

The instrument is called a "Lenonometer" (Sp?)

You simply place the "un-known" lens in the instrument and
"neutralize" the lens.

With a "Spherical" lens the results are generally to 1/4 diopters.

With a more complex (Cyl.) the results are less accurate -- but can be
made.

Enjoy,

On Oct 25, 5:48 am, LEESA <taylorlee... at (no spam) gmail.com> wrote:

Is there a name of the process where an optician can figure out the
prescription of a pair of glasses?

Is this hard to do? Can any optician do it and most importantly, can
it be done with precision and accuracy?

Thanks in advance

LEESA (I)- Hide quoted text -

- Show quoted text -[/quote]

Otis...

Posted: Sun Oct 25, 2009 5:32 am

Guest

Mike,

I responded to LEESA's question.

Don't be stupid about this.

If LEESA did not like the answer -- it is up to HER to say so -- not
you.

I RESPECT her intelligence on this issue -- you obviously do not.

Second-opinion best,

On Oct 25, 11:27 am, "Mike Tyner" <mty... at (no spam) mindspring.com> wrote:
[quote]"Otis" <otisbr... at (no spam) embarqmail.com> wrote

No, it is not difficult to determine the refractive STATE of the eye.

See, it's reckless to answer every question, when you have no training or
experience.

You thought she asked about "refraction." She didn't.

(You don't like to call it "refraction" because you don't have any training
or experience.)

She's asking about "neutralizing."

(You won't like that term either because you have no training or
experience).

You simply need a trial-lens kit and a Snellen to do it.

Now, you don't know it but you've actually hit on the explanation for the
term "neutralizing." It's because, before instruments like the B&L
Lensometer, lenses were measured by matching them with known lenses of
opposite power, such that the motion of magnification was "neutralized" when
looking through the paired unit.

I know I lost you, but it's really very simple.

Say you have glasses that are -8.00, but we don't know the actual power.

Say I have a trial set with +7.50, +8.00, and +8.50.

One-by-one, I hold your -800 up, sandwiched against one of my high-plus
lenses, and look through the combination at some distant object. When I move
the paired lenses side-to-side, as a unit, the image I see through them will
move also, because of magnification or minification, unless the lenses match
exactly.

If I sandwich your -800 with a +850, the combination has a value of +050 and
there is positive magnification and excessive motion. If I combine
your -800 with a +750, there is a -050 net power that yields negative mag
and _reduced_ motion. If I combine your -800 with a +800, there is NO
motion, so we say the lenses are NEUTRALIZED.

Instruments like the lensometer also "neutralize" but they change the power
of the "neutralizing" lens rather than switching lenses.

The instrument used in an ODs office is an "enhanced" trial lens kit.

That's for measuring EYES, not glasses.

But the process is to find a lens that "sharpens" your vision to
your satisfaction.

That's another process. You don't have any training or experience with that,
either.

-MT[/quote]

Neil Brooks...

Posted: Sun Oct 25, 2009 6:05 am

Guest

On Oct 25, 9:32 am, Otis <otisbr... at (no spam) embarqmail.com> wrote:
[quote]Mike,

I responded to LEESA's question.
[/quote]
Nah. You just wrote whatever you felt like writing ... and
demonstrated beyond doubt that you had NO idea what she was asking.

[quote]Don't be stupid about this.
[/quote]
Says s.m.v.'s resident absolute idiot.

More meds, Otis. It's time.

Oh.

Gee.

Otis deleted his original "reply." Shocked, I am. Don't worry,
Otis. Mike memorialized your stupidity for all to see.

Mike Tyner...

Posted: Sun Oct 25, 2009 9:27 am

Guest

"Otis" <otisbrown at (no spam) embarqmail.com> wrote

[quote]No, it is not difficult to determine the refractive STATE of the eye.
[/quote]
See, it's reckless to answer every question, when you have no training or
experience.

You thought she asked about "refraction." She didn't.

(You don't like to call it "refraction" because you don't have any training
or experience.)

She's asking about "neutralizing."

(You won't like that term either because you have no training or
experience).

[quote]You simply need a trial-lens kit and a Snellen to do it.
[/quote]
Now, you don't know it but you've actually hit on the explanation for the
term "neutralizing." It's because, before instruments like the B&L
Lensometer, lenses were measured by matching them with known lenses of
opposite power, such that the motion of magnification was "neutralized" when
looking through the paired unit.

I know I lost you, but it's really very simple.

Say you have glasses that are -8.00, but we don't know the actual power.

Say I have a trial set with +7.50, +8.00, and +8.50.

One-by-one, I hold your -800 up, sandwiched against one of my high-plus
lenses, and look through the combination at some distant object. When I move
the paired lenses side-to-side, as a unit, the image I see through them will
move also, because of magnification or minification, unless the lenses match
exactly.

If I sandwich your -800 with a +850, the combination has a value of +050 and
there is positive magnification and excessive motion. If I combine
your -800 with a +750, there is a -050 net power that yields negative mag
and _reduced_ motion. If I combine your -800 with a +800, there is NO
motion, so we say the lenses are NEUTRALIZED.

Instruments like the lensometer also "neutralize" but they change the power
of the "neutralizing" lens rather than switching lenses.

[quote]The instrument used in an ODs office is an "enhanced" trial lens kit.
[/quote]
That's for measuring EYES, not glasses.

[quote]But the process is to find a lens that "sharpens" your vision to
your satisfaction.
[/quote]
That's another process. You don't have any training or experience with that,
either.

-MT

Mike Tyner...

Posted: Sun Oct 25, 2009 9:33 am

Guest

"Otis" <otisbrown at (no spam) embarqmail.com> wrote

[quote]With a more complex (Cyl.) the results are less accurate -- but can be
made.
[/quote]
The results are more difficult to obtain, three results instead of one.

That does not mean "less accurate."

Unless it's done by someone with inadequate training or experience.

-MT

Mike Tyner...

Posted: Sun Oct 25, 2009 9:43 am

Guest

"Otis" <otisbrown at (no spam) embarqmail.com> wrote

[quote]Don't be stupid about this.
[/quote]
Stupid is answering every question with irrelevant and misleading
information.

[quote]If LEESA did not like the answer -- it is up to HER to say so -- not
you.
[/quote]
If you write stupid answers, I'm going to tell you. Get used to it or go
away.

Leesa deserves to know that you have no training or experience.

[quote]I RESPECT her intelligence on this issue -- you obviously do not.
[/quote]
I respect training and experience.

You have none and you choose to answer every question.

That's stupid. The pot calling the kettle black. Irony.

-MT

Salmon Egg...

Posted: Sun Oct 25, 2009 5:20 pm

Guest

In article
<1a713656-4155-4d5f-8fde-c34155040b87 at (no spam) d4g2000vbm.googlegroups.com>,
LEESA <taylorleesa0 at (no spam) gmail.com> wrote:

[quote]Is there a name of the process where an optician can figure out the
prescription of a pair of glasses?

Is this hard to do? Can any optician do it and most importantly, can
it be done with precision and accuracy?

Thanks in advance

LEESA (I)
[/quote]
Gee Leesa. Have you made any attempts to answer any of your questions
without depending on the kindness of strangers?

It is called measurement. There are many ways of doing so. The equipment
and accuracy is limited by cost and not technology.

Wikipedia, Google, and libraries should be your friends.

Bill

--
As the years go by, dying just before having to fill out a tax return has merit.

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