How do you mathematically convert a script taken w/ a minus phoropter to plus phoropter measurements

How do you mathematically convert a script taken using a phoropter w/
minus JCC lenses to plus cylinders? I mean, how do you write a script
that uses a plus cylinder lens instead of a minus?
Like, these two scripts are equivalent, but one uses a minus cylinder,
and the other uses plus cylinders:

Sph: +2.00; Cyl: +1.00; Axis:090
Sph: +3.00; Cyl: -1.00; Axis: 180

Like, write this using plus cylinders:

OD: Sph: -3.00; Cyl: Sph; Axis: Bal.; Prism: Bal.
OS: Sph: -3.75; Cyl: -1.00; Axis: 168; Prism: 0

Thanks!!!

 

I'd like to see if I understand the conversion correctly, eben though I
don't really know what I'm doing, so:

-3.75 / -1.00 @ 168 becomes
-4.75 / +1.00 @ 75

Is that right?

Dave

 

The formula is:

add the sphere power to the cylinder power (1st and 2nd
numbers) for a new sphere total, reverse the sign of the cylinder
power, add or subtract 90 (so the new number is less than or equal
to 180) for the new axis.

 

I'm not so sure about that, since it came from you...

Anyone else to confirm/disafirm?

 

od -300
os -475 +100 x 78

 

Umm, yeah. I meant 78 degrees.
I may have been reading that as 165, not 168. I hope.

Dave

 

WTF do you want this crap for? No-one uses plus cyl - except for some
stupid ophthals. All labs grind in minus cyl form, i.e. cyl ground on
the back surface, and have done so for the past 40 years. Anyone
writing scripts in plus cyl form is an idiot as it MUST be converted
at some point to make the Sx. This adds to error and the wrong script
being made.

 

Dear Catman,

Subject: Your respect for OPHTHAMOLOGISTS, and
their opinion.

CatMan> WTF do you want this crap for? No-one uses plus cyl - except
for some stupid ophthals.

Otis> I am certain these ophthmolgists will be highly
impressed by your statements about them.

 

Again, Mike you LEAP to the wrong (and your exclusive)
conclusion.

I have great respect for ophthamologist -- in the context
of medicine.

Further, I do not use the foul language that CatMan uses.
I may disagree with a man concerning his opinion on
a subject -- but I do not disrespect him -- as CatMan
does on a continuous basis.

Otis

 

Diddums.

You are a waste of space Cletis.

As explained already, plus cyl notation is wrong, outdated and
technically invalid. ANyone using plus cyl notation is writing an
incorrect script as lenses can't be made for these scripts.

Do I need to further explain this to your tiny brain????

 

I just wondered about what the formula was.

 

Dear Mike,

You indeed have your OPINION, that the fundamental
eye will not change its refractive STATE when
you place a -3 diopter lens on it.

I think your concept of the natural eye is a scientific
failure -- and disproven to boot.

There are ophthamologists who agree that it
would be WISE for the person to begin using
the plus (at the threshold) to keep their
vision clear doing the school years.

But the real issue is whether the person himself
is willing to make that type of commitment.

And that is indeed the point.

Obvously "Brainy" is not a candidate for
prevention, by ANY METHOD -- Bates,
plus, or a combination of the two.

So she loves that minus lens -- and does
not want to be disturbed by "contrary" scientific
concepts.

Yeah, you and Brainy were made for each other.

At least the Bates people have a more open
mind that you do towards PREVENTIVE methods.

Just one man's opinion.

Otis

 

Nice straw man argument, Uncle Otie: arguing against something that
NOBODY said.

Does that make you feel special -- sort of like your Librium??

DO you only find it possible to argue against things that you make up,
rather than argue against the ACTUAL position of a person?

It would appear so.

Do you mean monkey eyes? Nobody here really talks about those but
you.

Really? Who, where, are they still practicing, and have they ever
done any controlled testing?

Are you off your meds again? Gosh, I hope not.

So your myopic niece, Joy Benson, is just a lazy slug? That's not a
very nice thing to say about your own niece, Uncle Otie, now is it?

 

Is that because they both have IOLs and are long past the age where
there is possibility of improvement?

 

If you have to ask, I would not be able to answer you at your level. If you
know anything about optics and anything about simple algebra, and one more
thing, it should be a snap. The one thing is that a cylindrical lens with
power P and another cylindrical lens oriented perpendicular to the first is
optically the same as a spherical lens of power P.

Bill

 

Good point, Mike.

You can add that if you do anything SLIGHTLY different AT ALL,
one pointed-headed person (you know who) will post
CHARGES against you. That alone will prevent
ANY LICENSED OD FROM TAKING ANY PREVENTIVE
STEPS --at all.

Yes, Mike I understand PERFECTLY why you are
excluded from instituting plus prevention.

But to clarify that issue, here are some remarks
by Judy on that subject:

+++++++++++++++

Dear Second-opinion Scientists,

Subject: When YOU are responsible.

I do not use the term Natural Vision Improvement -- because
that implies that you need some "third party" to check
it.

I DO use the term "Natural Vision Clearing", because
I intende that you:

1. Read your Snellen, and confirm the Snellen
line that you read.

2. You understand the explict and legal requirement
of Visual Acuity stated by the DMV in almost all
states. And that is 20/40, which means EXACTLY
that you read, at 20 feet, 3/4 inch letters.

Thus if you confirm your Snellen at 20/60 (let us
say), and confirm that a -1 diopter lens clears
the 20/20 line, then your refractive STATE is -1 diopter.

If you work with these PREVENTIVE methods (Bates,
the plus, or BOTH), and working with your
IVAC Snellen, you confirm you cleared the
20/40 line, then you would pass the state
DMV.

These are actions you can take care of personally.

Once all medical issues are cleared off the
table, it then becomes a matter of having
the motivation to do this work in a persistent
and consistent manner.

If you are successful (as per the above), and
pass the DMV level test, then you simply
do not need the involvement of a "medical" person
at all.

(But the involvement of a STRONG plus-prevention
professional like Steve Leung would be
advised.) See:

www.chinamyopia.org

Here are the reasons why Dr. Judy can not
recommend preventive measures -- for your interest.

+++++++++++++++++

Re: Do All doctors think EXACTLY the same way?


Otis> And, by the way, I advocate that you always
have periodic exams. What I suggest it that
after the exam, (an the eye at 20/50 -- with
the possibility of self-clearing) that these
methods be discussed. It would be very easy
for an OD to say, "... you have 20/50. You
are in high school, and we know that the
eye goes "down" at -1/2 diopter per year. If you
wish to prevent, or clear, then click on
i-see and explore the concept and suggestions.
If you can clear your Snellen to PASS the
DMV requirement, then that will prevent
the development of stair-case myopia for you.

Majority-opinion OD Judy says:

Judy> Please do not complain about doctors not recommending NVI or
suggest that it would be easy for them to do so. As I have pointed out
before to you, it is not so easy. Licensed professionals have a
fiduciary duty to their patients; they must be careful to provide
advice that is in accordance with generally accepted standards of
practice and which is backed by published science.

[This depends on EXACTLY what you mean by science
as it concerns the dynamic nature of the fundamental eye.
I agree that YOU can never help a person with prevention -- and
the person will simply have to figure it out for himself.
I also ACCEPT that you remove yourself from this issue
by your reasons. OSB]

Judy> When there are published controlled human clinical trials of
methods of vision improvement such as plus lens therapy, cognitive
therapy,
accupuncture, the Myopter, Bates exercises, supplements, herbals,
massage, ayurvedic treatment showing that they are safe and
effective, then ODs will recommend them. Until then, they won't.

[Fine -- with me. Then again, the person must look at all of this, and
accept YOUR determination that you can not help anyone with plus-
PREVENTION, because it depends, not on you, but the insights of the
person himself. If he clears his Snellen (refractive STATE moves
positive), and passes, the Snellen, then there is no need for your
involvement at all. This is of course what
Dr. Colgate understood and did. But he was a very intelligent
scientist -- and knew the optics and behavior of the
natural eye. OSB]

Judy> This forum (i-see) functions very well for people to exchange
their opinions and experiences but don't expect doctors to recommend
it.

[I certainly do not expect you to recommend a course of action that
requires that the person himself make this type of choice. That does
become
a matter of the person choosing for himself the plus-preventive method
-- of which you will never have any involvement with -- for obvious
reasons. OSB]

Judy> A doctor's recommendation carries a weight of approval of and
agreement with content and cannot be done with an open content forum
like I-see.

[And to explain these issues in an office in five minutes would be
impossible. I think this DEFINES the issue of individual empowerment,
where the person make a choice of controling his refractive STATE
himself. And that is an issue of science as the person understand it.
OSB]

Just one man's opinion.

Otis

Judy

++++++++

 

Nice straw man argument there, too, Uncle Otie. Was that one a result
of too MUCH librium or too little?

I asked the State of Pennsylvania to investigate YOU and only YOU. You
were practicing medicine without a license. You really still are.
They're just waiting for sworn statements from a few of your victims
to prosecute.

Since you're pathological, you'll provide more victims ... eventually.
It's a statistical certainty.

You COULD continue lying about Mike's position, but I'VE seen him SAY,
repeatedly, that IF IT WORKED, he'd use it, so ....

You're a liar, as always.

Are you pathologically incapable of telling the truth??

 

snip

So first Otis says:

"What I suggest it that after the exam, (an the eye at 20/50 -- with
the possibility of self-clearing) that these methods be discussed. It
would be very easy for an OD to say, "... you have 20/50. You are in
high school, and we know that the eye goes "down" at -1/2 diopter per
year. If you
wish to prevent, or clear, then click on i-see and explore the concept
and suggestions"

Then, after I explain to him, yet again, why doctors can't do this he
says:

" I certainly do not expect you to recommend a course of action that
requires that the person himself make this type of choice. That does
become a matter of the person choosing for himself the plus-preventive
method"

So Otis, are you finally convinced that doctors cannot recommend "plus
prevention"? Will you now stop posting comments insisting that, in
your opinion, doctors should tell their myopic patients about the
various unproven therapies? Can we hold you to your last comment?

Dr Judy

 

How can you say that, Otis? Is my bionic eye no longer natural? Is
it not fundamental? And above all, is it not dynamic? Besides, what
about my other eye?

But no, you rush to exclude me in a rather discriminatory way, while
my myopia is clearing up rapidly as I continue to laugh. This is not
fair, Otis. My dynamic bionic eye changes its fundamental STATE by
applying pressure on the eyeball when I laugh so much.

You owe me an apology, Otis. I am serious about it, even when I am
sarcastic as some say without any scientific evidence.