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my glasses have barrel distortion

 
 
Morten S
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      01-26-2004, 02:53 AM

i got a new pair of glasses last week, they are -4.0 on both eyes.
beeing a contact lense user for years, the first thing I noticed with the
glasses was the extreme barrel distortion.
My optician adjusted the glasses and this made them a tad better...but the
distortion is still there.

is it possible to make -4.0 glasses WITHOUT any barrel distortion?
dont the glasses-makers have tools that checks this before handing out their
glasses to their customers?


 
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Repeating Rifle
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      01-26-2004, 05:23 AM
in article bv1vem$nduml$(E-Mail Removed)-berlin.de, Morten S at
http://www.optometryforums.com/(E-Mail Removed) wrote on 1/25/04 6:53 PM:

>
> i got a new pair of glasses last week, they are -4.0 on both eyes.
> beeing a contact lense user for years, the first thing I noticed with the
> glasses was the extreme barrel distortion.
> My optician adjusted the glasses and this made them a tad better...but the
> distortion is still there.
>
> is it possible to make -4.0 glasses WITHOUT any barrel distortion?
> dont the glasses-makers have tools that checks this before handing out their
> glasses to their customers?
>
>

First, I am not a vision professional. My opinion, however, is that you will
get used to the distortion. That is, the mind and brain can compensate for
your distortion.

I have heard of experiments with glasses designed to invert the image formed
on the retina. Supposedly, after a while, that was no longer a
disorientation problem. I have had something like that happen to me.

Bill

 
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Jan
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      01-26-2004, 03:21 PM

"Morten S" <(E-Mail Removed)> schreef in bericht
news:bv1vem$nduml$(E-Mail Removed)-berlin.de...
>
> i got a new pair of glasses last week, they are -4.0 on both eyes.
> beeing a contact lense user for years, the first thing I noticed with the
> glasses was the extreme barrel distortion.
> My optician adjusted the glasses and this made them a tad better...but the
> distortion is still there.
>
> is it possible to make -4.0 glasses WITHOUT any barrel distortion?
> dont the glasses-makers have tools that checks this before handing out

their
> glasses to their customers?
>

Morten,

The barrel distortion is caused by the distance between the lens and the
pupil.
A lens ( your contactlens) with the aperture (your pupil) at the same place
(or nearly to keep it simple) gives no distortion as you mentioned.
A minus lens (your glasses) placed before the aperture (your pupil) at a
greater distance gives a barrel shaped distortion.
And yes, a plus lens gives a pillow shaped distortion when wearing glasses.

It is not possible to make glasses without this distortion but you could try
to position your glasses as near as possible to the eyes.

If you wear your glasses constantly, you get used to this distortion (your
brains wil fix the job), but if you change regularly between your
contactlenses and the glasses you might keep the distortion problem.

Maybe this answer helps,

Jan (normally Dutch spoken)


 
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Rishi Giovanni Gatti
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      01-26-2004, 03:42 PM
Jan wrote:

> If you wear your glasses constantly, you get used to this distortion (your
> brains wil fix the job), but if you change regularly between your



Look what this man says: YOUR BRAIN WILL FIX THE JOB!!!


Now, if the brain can fix jobs, why cannot fix imperfect sight?

It can fix it.

--
Please visit
http://www.stores.ebay.it/juppiterconsultingrishi
and you can buy a replica of the Original Dr. Bates book
"Perfect Sight Without Glasses"
and if you are interested, join the group
http://health.groups.yahoo.com/group/PerfectSight/
 
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CLEFER
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      01-27-2004, 08:09 AM


Morten S wrote:

> i got a new pair of glasses last week, they are -4.0 on both eyes.
> beeing a contact lense user for years, the first thing I noticed with the
> glasses was the extreme barrel distortion.


Interested in your reason for switching.
I have recently gone the other way but need both, but I do not get distortion..
Will you be trying to use both?

 
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Morten S
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      01-28-2004, 12:58 AM

> Morten S wrote:
>
> > i got a new pair of glasses last week, they are -4.0 on both eyes.
> > beeing a contact lense user for years, the first thing I noticed with

the
> > glasses was the extreme barrel distortion.

>
> Interested in your reason for switching.
> I have recently gone the other way but need both, but I do not get

distortion..
> Will you be trying to use both?


I use contacts when im out in public and glasses at home...


 
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Otis Brown
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      01-30-2004, 05:13 AM
"Morten S" <(E-Mail Removed)> wrote in message news:<bv1vem$nduml$(E-Mail Removed)-berlin.de>...

Dear Morten,

There are many OD who love to give you astigmatism
"correction".

That is your "barrel distortion.

Go back and ask for "spherical" lenses.

If he will not do it, please post his "reasons".

[Or "rationalizations" depending on how you
look at it.]

Best,

Otis
Engineer




> i got a new pair of glasses last week, they are -4.0 on both eyes.
> beeing a contact lense user for years, the first thing I noticed with the
> glasses was the extreme barrel distortion.
> My optician adjusted the glasses and this made them a tad better...but the
> distortion is still there.
>
> is it possible to make -4.0 glasses WITHOUT any barrel distortion?
> dont the glasses-makers have tools that checks this before handing out their
> glasses to their customers?

 
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Jan
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      01-30-2004, 08:08 PM
Otis,

In earlier messages posted here you mentioned your knowledge about
photographic cameras.
On of the known facts in photography is the distortion "barrel'' or the
opposite "cushion" due to the position of the aperture and the position of
the principal plane of the lens(system).
The optic industry made special design lenssystems wich have the aperture at
the same place as the principal plane and then there is no "'barrel" or
"cushion" distortion.
It is about spherical lenses Otis, not toric ones.

Jan (normally Dutch spoken)

"Otis Brown" <(E-Mail Removed)> schreef in bericht
news:(E-Mail Removed) m...
> "Morten S" <(E-Mail Removed)> wrote in message

news:<bv1vem$nduml$(E-Mail Removed)-berlin.de>...
>
> Dear Morten,
>
> There are many OD who love to give you astigmatism
> "correction".
>
> That is your "barrel distortion.
>
> Go back and ask for "spherical" lenses.
>
> If he will not do it, please post his "reasons".
>
> [Or "rationalizations" depending on how you
> look at it.]
>
> Best,
>
> Otis
> Engineer
>
>
>
>
> > i got a new pair of glasses last week, they are -4.0 on both eyes.
> > beeing a contact lense user for years, the first thing I noticed with

the
> > glasses was the extreme barrel distortion.
> > My optician adjusted the glasses and this made them a tad better...but

the
> > distortion is still there.
> >
> > is it possible to make -4.0 glasses WITHOUT any barrel distortion?
> > dont the glasses-makers have tools that checks this before handing out

their
> > glasses to their customers?



 
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Otis Brown
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      01-31-2004, 03:00 PM
"Jan" <(E-Mail Removed)> wrote in message news:<401ab9ac$0$3262$(E-Mail Removed)>. ..

Dear Jan,

Yes there is a difference between "barrel" and astigmatism.

But when a layman looks through a lens with substantial
astigmatism cut, and rolls the lens and sees the
distortion of distant objects produced by that lens,
he tends to call it "barrel". Under that circumstance,
you must use HIS discription to talk to him.

Best,

Otis

******


> Otis,
>
> In earlier messages posted here you mentioned your knowledge about
> photographic cameras.
> On of the known facts in photography is the distortion "barrel'' or the
> opposite "cushion" due to the position of the aperture and the position of
> the principal plane of the lens(system).
> The optic industry made special design lenssystems wich have the aperture at
> the same place as the principal plane and then there is no "'barrel" or
> "cushion" distortion.
> It is about spherical lenses Otis, not toric ones.
>
> Jan (normally Dutch spoken)
>
> "Otis Brown" <(E-Mail Removed)> schreef in bericht
> news:(E-Mail Removed) m...
> > "Morten S" <(E-Mail Removed)> wrote in message

> news:<bv1vem$nduml$(E-Mail Removed)-berlin.de>...
> >
> > Dear Morten,
> >
> > There are many OD who love to give you astigmatism
> > "correction".
> >
> > That is your "barrel distortion.
> >
> > Go back and ask for "spherical" lenses.
> >
> > If he will not do it, please post his "reasons".
> >
> > [Or "rationalizations" depending on how you
> > look at it.]
> >
> > Best,
> >
> > Otis
> > Engineer
> >
> >
> >
> >
> > > i got a new pair of glasses last week, they are -4.0 on both eyes.
> > > beeing a contact lense user for years, the first thing I noticed with

> the
> > > glasses was the extreme barrel distortion.
> > > My optician adjusted the glasses and this made them a tad better...but

> the
> > > distortion is still there.
> > >
> > > is it possible to make -4.0 glasses WITHOUT any barrel distortion?
> > > dont the glasses-makers have tools that checks this before handing out

> their
> > > glasses to their customers?

 
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Otis Brown
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      01-31-2004, 06:31 PM
"Mike Tyner" <(E-Mail Removed)> wrote in message news:<ZKPSb.4603$(E-Mail Removed) link.net>...
> "Otis Brown" <(E-Mail Removed)> wrote
>
> > he tends to call it "barrel". Under that circumstance,
> > you must use HIS discription to talk to him.

>
> So Fincham should be rewritten because pilots use "barrel" differently? In
> optics, "barrel" is pretty well defined, if you bother with definitions.
>
> Should my urologist say "Woody" so I'll know what he means?
>
> -MT


Good point. Exact language -- depends on fundamental
definitions.

If in science I wish to establish that the natural
eye is dynamic, I am not going to use ORGANIC DEFECT
to describe the refractive states that I am measuring.

The difference is in the assumptions of the words
you are using.

Pure and fundamental science is profoundly different
that "health care".

Hope you have the sophistication to understand that
difference.

Best,

Otis
 
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