New glasses - like reading lines in a fun house mirror

Howdy,

I got new glasses a few days ago.

Prescription: R: Sphere -1.25 Cylinder -.75 Axis 115
L: Sphere PL Cylinder -.75 Axis: 095
Add +2.25

I haven't a clue what the above numbers mean.

Now the lines on a page appear wavy. Sometimes. Sometimes the lines
are ok, then become very wavy.

I understand that I now have a correction for astigmatism, the
previous glasses I had did not have this correction and there was no
wavyness at all, just a bit of blur of small type.

I am told that it may take some time to get use to this - but I cannot
believe it. If lines get wavy thru these lenses today - can I really
expect that they will not get wavy next week??

I am considering going to a new optometrist - but this can get pretty
expensive since I've already had the exam and have purchased two sets
of glasses.

Can anyone enlighten me??

rgds/Bob

 

I'm not a pro, and I'm not so sure about the "wavy", but whether lines are
straight or not has more to do with the brain than with the glasses and
eyes. When our eyes send images to the brain, the brain has learned what
"straight" means and will make that determination. When you get new
glasses, especially with a change in astigmatism, you are sending
different images to the brain. Even though they may be more accurate
images, the brain still needs to relearn what is straight and what isn't.
This takes a few days.

 

This prescription is progressive - and is not the first I've had of this
type which I
find considerable better than the glasses with the line for reading. I don't
know
off hand the correction/prescription for the last pair of glasses, but I
know there
was a big change in the right eye. I will see if I can find the old
prescription.

The waviness on the line of text varies from rolling up an down across the
page
to a falling off of the line, that is, as if the line on the right side is
further away, like
the page is falling off or slanting to the right.

Thanks.
rgds/Bob

 

Dear Bob,

Subject: Wavy lines -- produced by "astigmatic correction"?

There is no absolute requirement that you be
"corrected" for astigmatism.

If the "wavy lines" give you a problem,
go back and ask for "spherical lenses".

If they will not do that for you -- then
let us know.

Best,

Otis

 

When you say wavy, do you mean a line looks squiggly or just curved?

Do walls lean, do floors slope? Do square pieces of paper look like a
parallelogram? If yes, give them a few weeks.

Apart from being wavy, is the print you are reading *clear*? and is long
distance vision clear? If so, persevere for a few weeks, then go back to
your prescribing optometrist, who *may* decide to reduce or eliminate
the cylinder component.

However if your vision is *blurry* as well as wavy, then there may be an
error in the specs, perhaps take them back sooner.

You should always give the original prescriber an opportunity to help
you out.

Dom

 

(Otis Brown) wrote in @posting.google.com:

Other than the comfort, well being, and visual acuity of the patient, of
course.

Scott

 

That's true. Of course, with some level of astigmatism you can't get a
driver's license (or pilot's license I suppose). Then again, there's no
requirement that people have a driver's license. Of course, your
employment opportunities are limited without one, not to mention quality
of life sometimes, but who needs a life? I knew a guy who needed fairly
minor surgery to take out a cancerous prostate. He chose not to. There's
no absolute requirement that you have a cancerous prostate removed
surgically. Of course, then he died. He actually thanked people for
allowing him to choose his own course of treatment. Of course they
couldn't have forced him, but they could have bugged him. It wasn't even
aversion to medicine, since he had been an RN in his previous job and
worked some years in a critical care unit.

And then what would we do?

 

Thanks for your reply,

If I understand you correctly, the correction for astigmatism which
causes the wavy lines is not required - but if it is not required, why
was it prescribed?

What broght me into the eye doctor was that I noticed some bluriness
of people's faces starting at about 25 feet - at about 50 ft there was
considerable blurines, and if I did not recognize profile and walk, I
could not make out the person. Does astigmatism cause this?

thanks/rgds/Bob

 

some snipping here:

Bob: Well, the waviness does come and go - especially when I move my
head - ie, just a tilt for more light for instance - will make the
lines
kind of fall off to the fight - then when I bring my head back
perfectly upright there appears to be a kind of upward undultation
(not a sexy one thought) in the line for a moment, kind of until I
really concentrate my eyes on the page.

Bob: Well, the new prescription did improve far vision - but I don't
know if it was a change in the overall prescription that improved the
far vision or the astigmatism correction - that's mainly because I
don't know what an astigmatism correction is. I would have asked if
the eye doc would have mentioned it to me!

Bob: If I give it time to adjust then, the problem will get worse?
Sorry I don't quite follow here and it seems a very important issue???

Thanks/rgds/Bob

 

Just what problem in vision is caused by astigmatism?

rgds/Bob

 

big snip -25

Just curved - either upward curve (the line going up and over a bump),
or kind of falling off to the left (disappearing into the distance
downward and left).

YES - that is also just exactly what is happening. What is it?

Words are perfectly clear, I'm just getting a bit of sea sickness
reading the lines as the curve up down and down and out. The far
distance is considerably improved. It is just at near and at computer
range where there is a problem.

I will.

Thanks/rgds/Bob

 

There is an assumption being made here that the astigmatism correction is
causing the distortion. That may or may not be. I'm not your OD (not
anybody's), but I've been examined many times. The OD is always working
to give the sharpest image. They give you the astigmatism correction that
gives the sharpest image.

Yes. It causes the image to not focus correctly on the retina.

 

Sounds like aniseikonia, a side effect of astigmatism correction which gives
the distortions you described. You can fix it quickly by changing the lens
power to remove the astigmatism correction (the cylinder power) and put up
with slightly blurrier vision, or better still give your eyes (your brain,
really) a few weeks to adapt. Then the lines and shapes will be straighter
plus you'll still have the clear vision.

These side effects are also possible with progressive lenses, but you
mentioned this is not your first pair. So I think the cylinder power is the
likely culprit --> wait & get used to it. If no improvement after 4 weeks of
full-time wear then go back to your optometrist.

Also might pay to have the frame adjustment double-checked.

Dom

 

This prescription is progressive - and is not the first I've had of this

Bob,

Its been said that when there are problems adapting to progressive
addition lenses, 90% of the time it's due to a less than optimum fit.
The percentage of my clients that have had problems with a .75
cylinder power is probably less than 0.1%. I would recommend a
thorough inspection of the eyeglasses for the correct Rx, and just as
importantly, that the lenses are positioned correctly in front of the
eyes.

Hope this helps





Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical

~~~~~~~~~~~~~~~~~~
"Science is a way of trying not to fool yourself."
- Richard Feynman

 

(BobW) wrote in

http://www.visionsimulator.com/astigmatism/

 

Dear Bob,

Subject: When is astigmatic "correction" needed?

The approach of using "correcting" astigmatism developed
because it was found that additional "sharpness" could
be achieved in some eyes by applying "cylender" at an
angle.

If you wish very, very sharp vision then of course
you can turn the dials of a phoropter and make
vision very sharp indeed -- sharper than
20/20 in some cases. But this is looking
through the small aperture of a phoropter
in a darkened room looking at a projected
Snellen chart. Thus your field-of-view
is sharply restricted.

When a person receives glasses cut for astigmatism,
he often complains of "wavy lines" and the like,
and is unhappy with this result. The normal
reaction is that he goes back to the OD,
and he is told, "you will get used to it".
If that satisfies you, then don't worry,
be happy.

Fortunately, there are some ODs who are
more reasonable.

My wife had her eyes checked, and had
the "astigmatism" added. She saw
the same result that you did. From
long experience, I was well aware of this
effect. Since the OD who provided the lens
knew of this effect, he basically suppled
a "spherical" prescription. The result
is that she passes all the required legal
requirements -- and avoids the headaches
produced by the "astgmatism" correction.

But this comes down to a "trade off".
If you are "corrected" an pass the
Snellen-DMV (the legal requirement)
then that might be an acceptable
alternative.

This is my opinion, of course, and
I always request "spherical" -- if
the measured astigmatism is less than
0.5 diopters.

You will have to make your own
choice.

You can expect the usual "explosion" from the
ODs on this site (but not all), so be
prepared for it.

Best,

Otis
Engineer

*****

 

I think we already knew that Otis is not the typical engineer.


:-(

 

Among eye doctors, engineers have a reputation for being most finicky,

Engineers are the most idiotic people: except for their own field of
interest, they understand nothing of the rest of the world.

 

I just got home for the optometrist with a new prescription in hand.

The old "new" prescription was:

Prescription: R: Sphere -1.25 Cylinder -.75 Axis 115
L: Sphere PL Cylinder -.75 Axis: 095
Add +2.25

The new prescription is:

R: Sphere: -1.50 Cylinder -.50 Axis 105
L: Sphere: -.25 Cylinder -.50 Axis 100
Add: 2.25

I'll get the new glasses tomorrow, I hope, and let you all know how it
works.

Meantime, The Dr. did not really offer an explanation as to why the readings
changed
from the first new prescription last Friday, to the new prescription today,
one week
later??

rgds/Bob

 

Otis> But of course! When there vision passes the 20/25
line, you can put them in a darkened room and
measure 20/100 or so. And indeed that WILL PRODUCE
very sharp vision for their child. If the person
asks for that -- then he should GET IT in more ways
than one.

Otis> Of course the child will then develop
stair-case myopia, but that in not your fault.
It is because of his BAD HEREDITY. Yes,
that is is -- blame his genetics.

Otis> Engineers look at the true facts to work
towards a better solution of a very-difficult problem.
An open and creative mind must necessarily be
part of that process.

Best,

Otis
Engineer