Author Topic: Over-prescription, efforts, and objective results.  (Read 4641 times)

Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1766
Over-prescription, efforts, and objective results.
« on: November 14, 2014, 04:57:29 AM »
Subject: How do you define success, objectively, to yourself?

Item:  Todd's remarks about his own experience in wearing a plus to successfully return his vision to normal.

Item: This is objective proof of success.  There is a great deal of science that simply confirms that anyone with 20/40 -- could get back to 20/20.  As he suggests - he had to do it himself.

The legal requirement of the DMV (USA), is that you must read the 20/40 line at 20 feet, with BOTH EYES OPEN.  (I would expect that a serious person would plan to continue to wear the plus, until he does much better than 20/40.)

I wear the plus, to not only retain 20/20 vision (self-measured) but a slight "positive status"  to keep my night vision in good shape.  I just do not bother an OD to make a measurement - that I do much more accurately myself.  I am certain that if I went to an OD, I would be seriously over-prescribed, or "wrongly prescribed".  I just do not need the expense of that situation -- that is of no help to me.  It will simply make my vision worse, not better in the long-run, if I wear a "wrongly prescribed" minus lens - all the time.

But if you are starting at 20/50 to 20/60, it is good to have a goal you can ACHIEVE, as you wear the plus.  It is also good to keep in mind that it took Todd six months to get where he wanted to be -- objectively.

COMMENT ON TODD'S REFRACTION AND VISUAL ACUITY:

OD -1.00 -0.50 x 95

Spherical Equivalent  -1.25 diopters (about 20/50)

OS -1.75 -1.00 x 93

Spherical Equivalent  -2.25 diopters (about 20/100)

For any real, objective measurement, you should do this conversion.  I always use a spherical lens, and ignore an "astigmatic" lens - that is totally not necessary - for me.


+++

Remarks by Todd Becker,,

Before starting with plus lenses and print pushing, my prescription was -1.00 in the right eye and -1.75 in the left. Including my correction for astigmatism, here is the full prescription I had at the last eye exam for which I have records (12/18/95):

OD -1.00 -0.50 x 95
OS -1.75 -1.00 x 93

It took me about 6 months to stop needing minus lenses and about a year to reverse myopia to where I am today. I don’t have a current diopter refraction, but using the Snellen chart I’m 20/20 in the right eye and 20/40 in the left.

There is no precise conversion to diopters, but it works out to approximately -0.00D in the right eye and -0.75 in the left. So in effect, I went down by about 1 full diopter in each eye. It may not sound like much, but becoming independent of glasses and lenses without any surgery was worth it.

Todd



« Last Edit: November 17, 2014, 07:44:13 PM by OtisBrown »

Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1766
Re: Over-prescription, efforts, and objective results.
« Reply #1 on: November 14, 2014, 07:33:00 PM »

Remarks on eye-exams.  Why checking your own Snellen is critical for successful prevention.

I know a lot of people do not want to take the responsibility to actually put up a bright Snellen, and determine what line they read 1/2 the letters correctly.

Todd has a very valuable "situation" which is called, "mono-vision".  It is normal for there to be a difference in refractive state - between the two eyes.  There are people who then try to "correct" something - that should not be "corrected".

Because of this "mono-vision", Todd will indeed keep excellent vision - both distance and near - though the age of 70.

That is why you must not panic - if the refraction of you eyes is slightly different.

The DMV, judges vision WITH BOTH EYE OPEN.  Todd has 20/20.  Does he need to "improve further"?

+++++

By Todd:

Shanon,

I’ve not had an eye exam since the 1990s. Why pay for something I don’t need?

I use plus lenses on occasion as a preventive measure when I’m doing a lot of reading, or as a “tune-up”. But 95-99% of the time I never use lenses of any kind.

People ask all the time why I’m satisfied with 20/20 in the right eye and 20/40 in the left. The answer is that this has allowed my right eye to be very sharp for distance vision and my right eye to “specialize” in very close up vision. So my slightly myopic right eye can read fine print and read close up in perfect focus, slightly better than my left eye.

In the technical terms this is called “mono vision”. That’s a misleading term because it suggests the loss of stereo vision which is absolutely not the case for me. The focal ranges of my two eyes are overlapping. At middle distances, both are in perfect focus. At the extreme, the “stronger” eye dominates. So the net effect is that I see with clear sharp vision from 6″ out to infinity. The range is of course somewhat less for each eye separately. But since I use both eyes, the net effect is no deficit at all.

I do periodically work on on trying to increase the range of each eye separately, by patching, winking or just holding my hand at an angle in front of one eye at a time. Just to maintain flexibility and reduce the natural tendency of the eye to accommodate less with the aging process. At age 58, I have a slight degree of presbyopia, but I think it is much less than that of most of my peers. Many of my friends of a similar age are dependent on plus lenses for reading or minus lenses for distance. I need neither.

So do I need to “improve”? I could probably work on increasing the range and flexibility of my eyes separately. But I really feel no need to improve, since with both eyes together I see everything with sharp clarity.

Todd

Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1766
Re: Over-prescription, efforts, and objective results.
« Reply #2 on: November 16, 2014, 05:28:25 PM »
Subject: So what happened to Todd's astigmatism?

Item: No one can predict results - of course - but astigmatism often is reduced or ends, when you confirm naked eye 20/20 on your own Snellen.

+++++

By Todd:

1. My astigmatism spontaneously vanished. I tested myself, as you can, using the astigmatic mirror. If you have astigmatism, lines at a certain angle will be darker than the others:

http://www.vision-training.com/en/Vision%20test/Astigmatism%20test.htm

2. I started using plus lenses about 15 years ago. Quite frequently during the first year, less so for the next several years, and now only on occasion — perhaps once a week for 15 or 30 minutes.

I have no idea what happened to Bill on the forum. People come and go. Some hang around longer, others check in every so often.

I think that double and multiple images (diplopia), when it appears slightly beyond the edge of blur but not within the focal field, is frequently a promising and useful phenonmenon, as I explained in my talk, slides 29-32. You can read the notes for those slide, posted beneath the slides and video above.

Todd

« Last Edit: November 17, 2014, 09:34:49 AM by OtisBrown »

Offline HansK

  • Jr. Member
  • **
  • Posts: 52
Re: Over-prescription, efforts, and objective results.
« Reply #3 on: November 18, 2014, 06:53:38 PM »
Hi Mr. Otis,

what do you think is really "over-prescription"? Glasses that enable you reading more than 20/20?

If I am myopic with -1.00 diopters measured and if I am able to read 20/20 with -0.5 diopters, I will still be myopic (-0.5 diopters) and I will recognize blur in the distance.

But if I get -0.75 and can read for example 20/15 and still be myopic with -0.25, do I have "over-prescription"? Because I still recognize (a slight) amount of blur in the distance.

And if I finally wear the -1.00 diopters measured, I will not recognize any degree of blur very far away. Why should this then be "over-prescription"?

As for me, I can read with -0.25 diopters almost the 20/20 line (sometimes easily, sometimes harder but still distinguishable) and I recognize the blur in the distance.
When I wear my -1.25 glasses for tests - sometimes, the image is too sharp and uncomfortable and sometimes A SLIGHT AMOUNT OF BLUR is distinguishable in the distance.

=> So what do you exactly mean by "over-prescription"? If someone can read 20/20, he has not a refractive state of 0.0 diopters. I can prove this on myself.

I asked this in this topic so everybody can profit.

Kind regards,
Hans

Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1766
Re: Over-prescription, efforts, and objective results.
« Reply #4 on: November 27, 2014, 06:53:40 AM »
QUESTION:  What is over-prescription?

1) Why does it happen?
2) How do you avoid being over-prescribed (if you are attempting to get back to at least 20/40, and eventually self-checked 20/20)?
3) Why should you make refractive measurements, yourself, to avoid deadly over-prescription?

Here is a presentation by an optometrist, using a "Phoropter".  This is a mechanized Trial-lens kit.  The machine is indeed complex, with means to measure astigmatism.  If you want 20/18, 20/15, and 20/10, then I say you are over-prescribed.  This is why people who pass the 20/40 line, are prescribed a -2 diopter lens, when they should be intelligent, and check themselves. 

https://www.youtube.com/watch?v=bUEFgxx-eY8

NOTES:

1) The "outer ring" is the pure-spherical measurement.
2) Note that about 90 percent of the time is taken up in measuring astigmatism.  Then he has to go back, and interact with the spherical measurement.  This is indeed time-consuming.
3) If you asked for a "lesser" minus, the OD would "fall apart", and insult your intelligence.  (Do not bother asking - check yourself.)
4) Notice that he states that he, "never checks both eyes together". Yet this is the real check, since we do not drive a car with one eye open.  This is why you have your own Snellen set-up, and why this OD MISSES THE POINT, of you needing to do prevention yourself.

Most of the expense of the Phoropter is taken up on measuring, astigmatism, and that is not necessary - under almost all circumstances. He would not wish to admit to that truth.   

I accept that I must personally pass the 20/40 line, (to avoid wearing a minus lens), but what is more difficult, is to convince myself to wear a "plus for near", and slowly get back to 20/20 (refractive state of 0.0 diopters).  For those who insist on 20/15 vision, and will be upset if they do not have it, then I would not advocate that they attempt to restore their distant vision with a plus.  From this video,  it is clear that "doing prevention yourself" would blow his mind, with the audacity of the concept.

A very wise OD described this over-prescription policy, as "poison".  He was correct, but no OD can resist that policy.

But the biggest step, is when you realized that only you can actually get back to 20/40, by avoiding the minus - as much as possible.

I have no "argument" with an OD in his office.  He has no time for prevention, and will not discuss it.  That only makes the effort even more personal, since prevention is something you do for yourself.

I can verify my own refraction, in about five minutes.  I totally accept that only I can control my own vision - myself - by understanding, wisdom and self-checking, both refraction and visual acuity.  No one is going to do it for me.

This video is NOT about medicine.  It is about you having the courage to make critical measurements -- yourself.  Very few people know what a "diopter" actually is.  By making measurements yourself, you would certainly find out, and know what you are doing.  This is to not "dispute" with an OD, far from it.  It is to make you technically competent, so you have the courage to continue to wear the plus, and, when you exceed the 20/40 line, to continue with the plus.  If you have 20/40 (at this time), and show to yourself you have 20/20 through a minus, you have "cleared off" all medical problems". The only issue then, is to continue with the plus -- persistently.

https://www.youtube.com/watch?v=9OUw5YkrNWw

No one ever said that this was going to be easy - did they.  Certainly -- never myself.

Most people simply do not have the fortitude to do prevention.  I accept that as a fact.  But then, you can not blame the OD for giving you a -2 diopter lens - when you have 20/40.  That FIRST excessive minus is indeed the "killer" of vision.  It is not intended that this should happen - but it always does.

« Last Edit: December 01, 2014, 11:35:04 AM by OtisBrown »

Offline HansK

  • Jr. Member
  • **
  • Posts: 52
Re: Over-prescription, efforts, and objective results.
« Reply #5 on: December 04, 2014, 08:31:51 AM »
Hi Mr. Otis,

physically, 0.0 diopters means that the eye has no far-point, right?

If I can read 20/20 and see still some blur in the distance, how can you state that this is a refractive state of 0.0 diopters?

And everytime I wake up after sleep, I see so much sharper for 5-10 minutes, and then the sharpness disappears...

I am still at the range of 20/30 to 20/40 (vision changes) and seeing through my -1.25 glasses, I still see a slight amount of blur in the distance. Well, I am using the plus about 1 1/2 months. Expecting results in that period of time is too much wanted, isn't it?

Especially after a long time with the plus on my eyes, I can see 20/30 (but kinda "ghosty", because it is the edge of sharpness and blur mixed together, hard to explain).

I recently checked my eyes with the glasses. With -1.25 on my eyes, I see 20/16 (1,2) and 20/13 (1,5) is like "well I recognize something but I cannot say what". When I increase the optical power of the lens (by changing the curvature of the glasses), I can see 20/13 (1,5) and everything is VERY SHARP. It is dark outside now and by changing the curvature of the glasses, I have also EXTREME SHARP NIGHT VISION. Achieving this without glasses would be a dream!!!!!!!!!

And since I started with the plus, I have never worn a minus, just for checking my visual acuity and checking if something changed, means never longer than 5-10 seconds.

Kind regards,
Hans

Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1766
Re: Over-prescription, efforts, and objective results.
« Reply #6 on: December 04, 2014, 10:04:08 AM »
Hi Hans,

I truly do not want to give you a "hard time" about prevention, because I think "just prevention" is very difficult.  But I always want to check myself, and consider *me* reading the 20/20 line on my Snellen, to be good vision.  If I want "better" then I will have to induce a change of about +1 diopter, (by wearing a plus 2 to 3 D for all close work, as long as I am in school).  There is no "rapid recovery", for the reasons I present. I never use the word, "cure", and I truly believe that if I wish to keep the vision I have, I must wear the plus for near.

I always appreciate your frustration.  There is NO DOUBT, but that any prevention (with a plus) is extremely difficult.  Because you your school work, you have already "gone down" by -1.25 diopters.  This is DOCUMENTED, in this analysis:

http://myopiafree.wordpress.com/study/

Read is carefully.  If you have any questions about how the data was developed, and the IMPLICATIONS of this science and data - let us know.

The plus was used on CHILDREN - not young adults, who could understand the need for basic prevention.  But they did not get out of it.

It is my suggestion, that a person at -1.25 diopters (self-measured, using the 20/20 line for reference) MIGHT be able to get a change of +1 diopters - in ONE YEAR.

So you are already down by -1 diopters. 

I believe in making all refractive measurements myself.  That saves an argument with an OD about what I am doing - and WHY I am doing it.

You want to measure relative-to the 20/10 line.  They you can use that as a reference - with you own test lenses, and your Snellen.

I prefer to "standardize" on the 20/20 line, since that meets all LEGAL requirements.

When I say refractive STATE, it  means that I have used that 20/20 line as reference, so that others can make their own measurements for the purpose of comparison - and for the person to make up his mind about what he is doing.

Physically, for me, self-measured 0.0 diopters, means exactly this.  I can objectively read the 20/20 line, naked eye.

THEN, to determine my refractive STATE, I hold up a +1/2 diopter, and see if I can read the 20/20 line THOUGH the plus lens.

If "yes" then I try a +3/4 diopter.  Then I can't read the 20/20 line, but I can read the 20/25 line.

My refractive STATE is +3/4 diopters.

This is a very conventional way to make objective measurements.

You are empowered to make these measurements -- any way you want to do it.

Currently, because my refractive STATE is +3/4 diopters, my semi-darkness vision - is very good.

In fact, I can read about 20/15, on that Snellen.

I do this  because I wish to verify OBJECTIVE CHANGE in my refractive state - myself.

Any vision better-than 20/40 allows me to avoid the minus (although I would have a -1 diopter for $7, until i got to 20/20.

I know you can see 20/15 though a -1 diopter.  But just getting to naked eye 20/20 - will take a lot of time.

Our eyes go DOWN at a rate of -1/2 doipter PER YEAR.  So the best we can expect, is our eyes to go "up" at +1/2 diopter per year.

That is what science tell me.

That is why I make my own measurements.

TODD'S EXPERIENCE:

He had about a -1 diopter and -2 diopter.

He does not have 20/10 vision.  Does he care about that issue.

He has 20/20 naked eye vision.

Now, is Todd objectively successful.



Hi Mr. Otis,

physically, 0.0 diopters means that the eye has no far-point, right?

If I can read 20/20 and see still some blur in the distance, how can you state that this is a refractive state of 0.0 diopters?

And everytime I wake up after sleep, I see so much sharper for 5-10 minutes, and then the sharpness disappears...

I am still at the range of 20/30 to 20/40 (vision changes) and seeing through my -1.25 glasses, I still see a slight amount of blur in the distance. Well, I am using the plus about 1 1/2 months. Expecting results in that period of time is too much wanted, isn't it?

Especially after a long time with the plus on my eyes, I can see 20/30 (but kinda "ghosty", because it is the edge of sharpness and blur mixed together, hard to explain).

I recently checked my eyes with the glasses. With -1.25 on my eyes, I see 20/16 (1,2) and 20/13 (1,5) is like "well I recognize something but I cannot say what". When I increase the optical power of the lens (by changing the curvature of the glasses), I can see 20/13 (1,5) and everything is VERY SHARP. It is dark outside now and by changing the curvature of the glasses, I have also EXTREME SHARP NIGHT VISION. Achieving this without glasses would be a dream!!!!!!!!!

And since I started with the plus, I have never worn a minus, just for checking my visual acuity and checking if something changed, means never longer than 5-10 seconds.

Kind regards,
Hans
« Last Edit: December 04, 2014, 10:37:48 AM by OtisBrown »

Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1766
Re: Over-prescription, efforts, and objective results.
« Reply #7 on: December 04, 2014, 10:48:46 AM »
Dear Hans,

Subject:  Why I do not say, "cure", only prevention for people who can still read the 20/40 line, and are in college.

I take plus-prevention to be the FINAL stage of recovery.  This is with reference to Dr. Alex's statement about the plus:

http://frauenfeldclinic.com/reader-questions-plus-lens-therapy/

But the real implication of a -5 diopter lens on a child is this.  HOW THE HELL DID THE CHILD GET DOWN TO -5 diopters?

The reason is in that STUDY, I just presented.  Is Dr. Alex successful?  I think he is great - but I just do not know if anyone is successful.

This is why I suggest that all serious people, working on their vision, OBJECTIVELY, read their own Snellen, and I would insist, have their own "test lenses" and confirm their own refractive state.

I know I am required to pass the 20/40 line - so I check myself.  If I have a problem with the 20/40 line, and OD will prescribe a -2 to -3 diopter lens.  If I wear it - that will destroy my vision - permanently.

So - what to do?

How do you avoid the minus?

But being reasonable, if 18 years old, and entering a four year college.  KNOWING for certain that you will go down by an additional -2 diopters in four years - and making plans to prevent that from happening.

That is what this discussion is all about.

Offline HansK

  • Jr. Member
  • **
  • Posts: 52
Re: Over-prescription, efforts, and objective results.
« Reply #8 on: December 04, 2014, 12:18:07 PM »
Hi Mr. Otis,

of course, NAKED 20/20 vision would be soo great! I would not need glasses - oh what a dream...

I am really shocked when I see people having -5 diopters. The person is blind without a minus!!! And the worst thing is wearing the FULL prescription while doing a lot of near work! I am really thankful that I discovered the method to change the refractive state of the eye.

When I first got my glasses, I have never worn them, except for seeing the blackboard in school (I was 14 years old).

Every time I wore my glasses - initially -1.00 diopters - I was very sad because I missed the sharp vision. But I did not like to wear glasses. So I decided to wear contact lenses and I did again a lot of near work. Then, my prescription increased and it is the same as today - about -1.25 to -1.50 diopters.

If I continued like most of the people with increasing prescriptions, where would I have been now? I do not want to think about it!

It is all logical, yes - but the most difficult and frustrating factor is motivation (including time).

Kind regards,
Hans

Offline Myoctim

  • Jr. Member
  • **
  • Posts: 56
Re: Over-prescription, efforts, and objective results.
« Reply #9 on: December 07, 2014, 04:44:48 PM »

When I say refractive STATE, it  means that I have used that 20/20 line as reference, so that others can make their own measurements for the purpose of comparison - and for the person to make up his mind about what he is doing.

Physically, for me, self-measured 0.0 diopters, means exactly this.  I can objectively read the 20/20 line, naked eye.

THEN, to determine my refractive STATE, I hold up a +1/2 diopter, and see if I can read the 20/20 line THOUGH the plus lens.

If "yes" then I try a +3/4 diopter.  Then I can't read the 20/20 line, but I can read the 20/25 line.

My refractive STATE is +3/4 diopters.

This is a very conventional way to make objective measurements.



Unfortunately I can't fully agree to that.
After recovering a bit I now can read the 20/20 line using my former undercorrected contacts and an additional pair of +0.5D reading glasses on my nose.

But when moving the chart to 25 ft away it all gets a bit blurry and I can't read the 20/25. Putting off the +0.5D I now easily can read 20/20 even from 26 ft. away.
When looking across the street I can read the street sign from 50 ft away in the dark but using the additional +0.5D it's only readable in daylight.

IMHO a refractive state of exactly 0.0D should allow us to get a "perfect focus" without needing an extra 0.25D to 0.5D boost by a small pupil, shouldn't it.

Also a person achieving 0.0D refractive state when reading a red snellen would be a bit myopic at a green one and even more myopic when looking at a blue one. So at which wavelength we define that 0.0D?

Offline HansK

  • Jr. Member
  • **
  • Posts: 52
Re: Over-prescription, efforts, and objective results.
« Reply #10 on: December 08, 2014, 08:59:12 AM »

When I say refractive STATE, it  means that I have used that 20/20 line as reference, so that others can make their own measurements for the purpose of comparison - and for the person to make up his mind about what he is doing.

Physically, for me, self-measured 0.0 diopters, means exactly this.  I can objectively read the 20/20 line, naked eye.

THEN, to determine my refractive STATE, I hold up a +1/2 diopter, and see if I can read the 20/20 line THOUGH the plus lens.

If "yes" then I try a +3/4 diopter.  Then I can't read the 20/20 line, but I can read the 20/25 line.

My refractive STATE is +3/4 diopters.

This is a very conventional way to make objective measurements.



Unfortunately I can't fully agree to that.
After recovering a bit I now can read the 20/20 line using my former undercorrected contacts and an additional pair of +0.5D reading glasses on my nose.

But when moving the chart to 25 ft away it all gets a bit blurry and I can't read the 20/25. Putting off the +0.5D I now easily can read 20/20 even from 26 ft. away.
When looking across the street I can read the street sign from 50 ft away in the dark but using the additional +0.5D it's only readable in daylight.

IMHO a refractive state of exactly 0.0D should allow us to get a "perfect focus" without needing an extra 0.25D to 0.5D boost by a small pupil, shouldn't it.

Also a person achieving 0.0D refractive state when reading a red snellen would be a bit myopic at a green one and even more myopic when looking at a blue one. So at which wavelength we define that 0.0D?

Hi Myoctim,

I went to the OD today and he fit me with -1.0 lenses, although I have -1.25 glasses at home and I see a little bit blurry with them. I ordered contact lenses and I will just wear them for distance activities (driving, being outside etc.).

With the -1.0 lenses, I achieved 20/16 vision WITH BOTH EYES, I was impressed. The room was dark. But I know I am still myopic, I recognize blur in the distance. I think with -1.5 I would have a PERFECTLY SHARP IMAGE.

According to Mr. Otis - if I would have improved by 1 diopter - I would be "emmetropic" (0.0 diopters, achieving 20/20). As I have said, I see some blur in the distance (especially in the night). In bright daylight - if I do not care, I will not recognize that blur, but I do.

0.0 diopters - that means to me that the eye has no far-point. Its far-point is infinity, so you do not see any blur in the distance.

But I have to say: If I improve by 1 diopter and I cannot improve further - I would take that! Although I would be still myopic, my visual acuity is great!

Kind regards,
Hans

Offline gekonus

  • Jr. Member
  • **
  • Posts: 84
Re: Over-prescription, efforts, and objective results.
« Reply #11 on: December 08, 2014, 09:33:48 AM »
Well Hans, maybe you're right about the emmetropic thing - "no edge of blur" , but if that is the case, then emmetropia is not 20/20. 20/20 isnt even perfect, its just normal , or average.
More like 20/10 or so.

Offline HansK

  • Jr. Member
  • **
  • Posts: 52
Re: Over-prescription, efforts, and objective results.
« Reply #12 on: December 08, 2014, 09:40:41 AM »
Well Hans, maybe you're right about the emmetropic thing - "no edge of blur" , but if that is the case, then emmetropia is not 20/20. 20/20 isnt even perfect, its just normal , or average.
More like 20/10 or so.

Emmetropia is - for me - a refractive state of 0.0 diopters. In emmetropia, a "edge of blur" does not exist. Mr. Otis has another opinion which I respect but I do not agree with him.

Kind regards,
Hans

Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1766
Re: Over-prescription, efforts, and objective results.
« Reply #13 on: December 08, 2014, 10:09:09 AM »

Hi Hans and Gekonus,

There are some words - that I avoid - or that cause major anger - if used.  This truly gets very bad, if you use words you do not understand, and then claim that you have "cured myopia".  Then the optometrist EXPLODES, and tells you that no one can "cure myopia", and gets into a huff about that issue.

I perceive the natural eye as dynamic.  Thus the natural eye can have either positive or negative (self-measured) refractive STATES, not "errors". 
The word, "emmetropia" is an INVENTED word, meaning very little.  It would be of value to have a definition that we can all agree to.

But I am indeed forced to use that word.  So if we want to use the word, "emmetropia", then I always insist in SELF-MEASURED, refractive state.  This does include your own four test-lenses.

It is my intention to make the person expert enough, so that he can avoid going to an OD, and get a -1.5 diopter lens - when he has 20/20 vision.

I know that an OD will always give you the strongest minus possible.  They call this "habit", "best visual acuity".  That may give you 20/10, but I would never call that "emmetropia".

Normal is called self-measured 20/20, using your OWN Snellen (both eyes open).  Now if you have 20/20, and can read the 20/20 line THOUGH a +1/2 diopter lens, your refractive STATE is in fact +1/2 diopters.  (This is very valuable, since you will probably have 20/18 and 20/15 vision, naked eye.)

Quite a few people are happy with 20/20 vision.

I personally hate the minus lens, and if I had 20/25 to 20/20 vision -- I would not be wearing a minus lens, or an "astigmatic" lens for that matter.

Here again is the issue of over-prescription.  I think any minus lens, worn all the time is deadly.  But we know if you have 20/40 vision (self checked) you are probably going to get a -2.5 diopter minus lens.  Is that what you want??  That truly does "kill" vision for the long term.

That is why there is a "fight" about defining "emmetropia".

I prefer to just use the word, "refractive state", and key off the 20/20 line.  For Hans, with all due respect, he wants to make 20/10, emmetropia, or what is called, "Best Visual Acuity".

But these debates are very good - because the begin to get some of these issues of personal responsibility into sharp focus.

We need MORE discussions of this nature - not less.


Well Hans, maybe you're right about the emmetropic thing - "no edge of blur" , but if that is the case, then emmetropia is not 20/20. 20/20 isnt even perfect, its just normal , or average.
More like 20/10 or so.

Emmetropia is - for me - a refractive state of 0.0 diopters. In emmetropia, a "edge of blur" does not exist. Mr. Otis has another opinion which I respect but I do not agree with him.

Kind regards,
Hans
« Last Edit: December 08, 2014, 10:21:47 AM by OtisBrown »

Offline HansK

  • Jr. Member
  • **
  • Posts: 52
Re: Over-prescription, efforts, and objective results.
« Reply #14 on: December 08, 2014, 11:05:21 AM »
Hi Mr. Otis,

of course - someone who can read 20/20 should never wear a minus - it is not necessary.

I wonder: Are there really people who can read 20/40 and get a -2.5 diopter lens? Well, that will indeed kill your vision.

I think prescribing to "emmetropia" (no edge of blur with the lowest amount of diopters) is not healthy (just for driving or safety reasons) because it locks your eyes and it freezes the opportunity to clear vision back to normal. If you spend then a lot of time doing near-work, you become "again" nearsighted (just how you started, the cycle repeats itself).

So you say you have a refractive state of 0.0 diopters when you achieve self-measured 20/20 vision. That would mean you see everything in focus (in distance), but that is not true.

Kind regards,
Hans