Author Topic: The Secret of Perfect Vision  (Read 38900 times)

Offline OtisBrown

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Re: The Secret of Perfect Vision
« Reply #75 on: March 01, 2013, 07:24:58 AM »
Hi John,

I often dreamed of a true prevention (recovery) study, where the person himself was taught how to 1) Meaure his visual acuity, and the 2) Accurately measure (to 1/4 diopter) his refractive status.  I know this will take a wise an motivated person - who will have the courage to make these measurements - but here is how *I* do it.  This simply by-passes the OD in  his office.

http://www.youtube.com/watch?v=CrfuLuibclY

This process is NOT "anti-medicine", but rather it is a desire on my part to take PREVENTIVE measures before I go to an ophthalmologist.  This I "divide", responsibility.  I am repsonsible for ALWAYS checking my visual acuity - to make certain I always PASS the 20/40 line.  (I know if I go  to an OD, I will get a -1 to -3 diopter prescription - which just makes matters far worse).  By personally measuring my refractive STATE myself (say at -1.0 diopters), I can simply order the lens from Zennioptical for $10, and AVOID WEARING IT - EXCEPT FOR DRIVING A CAR.  But I would enspire myself to wear the plus, until I began to read the 20/25 to 20/20 line (refractive state = zero).  That is why I consider this "measurement system" the best - and most accurate.


Actually the link above goes to a page that has a link to the calculator. HERE is where the calculator is found:

http://frauenfeldclinic.com/focal-calculator/calc.html

Offline Steven

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Re: The Secret of Perfect Vision
« Reply #76 on: March 03, 2013, 08:09:11 AM »

Thanks Steve for all your thorough number crunching. I've only posted the above 20/40 idea you present.

I know I am -1.25D as measured by an OD.   I am also -1.25D if I use test lenses and wish to obtain maximum acuity on my snellon, meaning I don't see blur even if I can't make out the 20/13 line.  I also use my edge of blur distance on the Frauenfeld calculator and get about -1.25 D.  I am generally 20/40 to 20/50 when I make no effort on my snellon.  That's why I wondered why you stated 20/40 made you a -2, given that I definately am not -2 (or worse) given I would approximate myself at 20/45 on the snellon "at rest". 

See This :

http://www.providencejournal.com/sports/red-sox/content/20120316-baseball-vision-when-20-20-eyesight-just-wont-cut-it.ece


In absolute terms 20/40 is -2 and you see perfectly clear images at maximum of 50 centimeters.
In absolute terms 20/50 is -2.5 and you see perfectly clear images at maximum of 40 centimeters.

20/20 in absolute terms is -1 and you can see perfectly clear images at maximum of 1 meter.

The maximum you can get is 20/8 that means -0.4 myopia and allows you to see perfectly clear images at maximum 2.5 meters and of course clean the Snellen line at 20/8.

I don't know what is the minimum hyperopia that is physically possible by the eye.
Does anyone know ?

While all the arithmetic is correct, I doubt the truth of the assertion that 20/40 is equivalent to being able to focus clearly at 0.5 meters. Why not 0.5 feet, or 0.5 inches? The fraction 20/40, if it can even be considered a fraction, is 20 feet/40 feet which is equal to the dimensionless number 0.5. So I see no reason whatsoever to expect that just clearing the 20/40 line implies myopia of -2.0.

The Snellen chart is 6 meters away but the 20/20 line has such big letters that you can see it from 6 meters. If you clear the 20/20 line you have -1 myopia.

The first step is 20/8 because that is the limit of the human eye.

All you need to do to reach 20/8 is to use a very strong plus until you reach -0.4.
But be careful not to push your eye to become too much hyperopic.

Please read this : http://en.wikipedia.org/wiki/Visual_acuity#Visual_acuity_expression

20/40 is same as 6/12 and equals 0.50 in decimal system.

Only LogMAR : http://en.wikipedia.org/wiki/LogMAR_chart considers 20/20 as 0. Plus values as vision loss and negative values as better than normal sight. But it is not used clinically.

http://www.optometricmanagement.com/articleviewer.aspx?articleid=71635

Offline johnlink

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Re: The Secret of Perfect Vision
« Reply #77 on: March 03, 2013, 08:16:15 AM »
The Snellen chart is 6 meters away but the 20/20 line has such big letters that you can see it from 6 meters. If you clear the 20/20 line you have -1 myopia.

How do you come to that conclusion?

Quote
20/40 is same as 6/12 and equals 0.50 in decimal system.

Yes but that 0.50 is a dimensionless number. It is NOT a number of diopters.

See http://en.wikipedia.org/wiki/Dimensionless_number for an explanation of dimensionless numbers.

See http://forum.gettingstronger.org/index.php/topic,443.0.html for a description of the relationship between visual acuity and refractive state.
« Last Edit: March 03, 2013, 10:32:49 AM by johnlink »

Offline OtisBrown

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Re: The Secret of Perfect Vision
« Reply #78 on: March 03, 2013, 10:11:52 AM »
Hi Steven,

First of all - congratulations on verifying you can read the 20/40 line with no minus lens on your face.  I know you "came back" from -2.5 diopters IIRC.

To me, that is a major goal in my life.  I truly hate the minus lens. But equally I value the knowledge of how to obtain it from Zenni, and use it with wisdom - when necessary.

Let me respond to your question.

Steven>  I don't know what is the minimum hyperopia that is physically possible by the eye.
Does anyone know ?

Otis> Yes - it is zero diopters - measured with a Snellen and trial-lens kit.

Otis





Thanks Steve for all your thorough number crunching. I've only posted the above 20/40 idea you present.

I know I am -1.25D as measured by an OD.   I am also -1.25D if I use test lenses and wish to obtain maximum acuity on my snellon, meaning I don't see blur even if I can't make out the 20/13 line.  I also use my edge of blur distance on the Frauenfeld calculator and get about -1.25 D.  I am generally 20/40 to 20/50 when I make no effort on my snellon.  That's why I wondered why you stated 20/40 made you a -2, given that I definately am not -2 (or worse) given I would approximate myself at 20/45 on the snellon "at rest". 

See This :

http://www.providencejournal.com/sports/red-sox/content/20120316-baseball-vision-when-20-20-eyesight-just-wont-cut-it.ece


In absolute terms 20/40 is -2 and you see perfectly clear images at maximum of 50 centimeters.
In absolute terms 20/50 is -2.5 and you see perfectly clear images at maximum of 40 centimeters.

20/20 in absolute terms is -1 and you can see perfectly clear images at maximum of 1 meter.

The maximum you can get is 20/8 that means -0.4 myopia and allows you to see perfectly clear images at maximum 2.5 meters and of course clean the Snellen line at 20/8.

I don't know what is the minimum hyperopia that is physically possible by the eye.
Does anyone know ?

While all the arithmetic is correct, I doubt the truth of the assertion that 20/40 is equivalent to being able to focus clearly at 0.5 meters. Why not 0.5 feet, or 0.5 inches? The fraction 20/40, if it can even be considered a fraction, is 20 feet/40 feet which is equal to the dimensionless number 0.5. So I see no reason whatsoever to expect that just clearing the 20/40 line implies myopia of -2.0.

The Snellen chart is 6 meters away but the 20/20 line has such big letters that you can see it from 6 meters. If you clear the 20/20 line you have -1 myopia.

The first step is 20/8 because that is the limit of the human eye.

All you need to do to reach 20/8 is to use a very strong plus until you reach -0.4.
But be careful not to push your eye to become too much hyperopic.

Please read this : http://en.wikipedia.org/wiki/Visual_acuity#Visual_acuity_expression

20/40 is same as 6/12 and equals 0.50 in decimal system.

Only LogMAR : http://en.wikipedia.org/wiki/LogMAR_chart considers 20/20 as 0. Plus values as vision loss and negative values as better than normal sight. But it is not used clinically.

http://www.optometricmanagement.com/articleviewer.aspx?articleid=71635


Offline Steven

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Re: The Secret of Perfect Vision
« Reply #79 on: March 03, 2013, 02:37:44 PM »
Thank you Otis for the answer. You remember correctly.

If you as a young kid take a small text and put it very close to your eyes, like closer then 5 cm you will start to see that as you get closer to 1 cm the image will blur almost completely. If you have myopia like me you can bring it up to 2 cm before it goes all blurry. So there is a physical limit in both looking up close and look up far away.

Quote
As in a photographic lens, visual acuity is affected by the size of the pupil. Optical aberrations of the eye that decrease visual acuity are at a maximum when the pupil is largest (about 8 mm), which occurs in low-light conditions. When the pupil is small (1–2 mm), image sharpness may be limited by diffraction of light by the pupil (see diffraction limit). Between these extremes is the pupil diameter that is generally best for visual acuity in normal, healthy eyes; this tends to be around 3 or 4 mm.

If the optics of the eye were otherwise perfect, theoretically, acuity would be limited by pupil diffraction, which would be a diffraction-limited acuity of 0.4 minutes of arc (minarc) or 20/8 acuity. The smallest cone cells in the fovea have sizes corresponding to 0.4 minarc of the visual field, which also places a lower limit on acuity. The optimal acuity of 0.4 minarc or 20/8 can be demonstrated using a laser interferometer that bypasses any defects in the eye's optics and projects a pattern of dark and light bands directly on the retina. Laser interferometers are now used routinely in patients with optical problems, such as cataracts, to assess the health of the retina before subjecting them to surgery.

a) So if you look far away you are limited by pupil diffraction & the size of the cone cells in the fovea. Maximum you can achieve is 20/8.
b) If you look very close you are probably again limited by the exact same 2 things because otherwise at 0 diopters you could see well no matter how close you put the text. (infinitely close and that is not true, because you can't see that close even if you are very young.)

Or it may be caused by the current elongation of the eye. When i had -4 i could see very close things even more clear than i do now.

But a perfectly healthy eye, can't see if you put the text extremely close to the eye.

The lens of the eye also seems to get harder as time passes according to some people. (Presbyopia)

Now to answer johnlink.

If you read the 20/40 line you will see everything clear at 50 cm (computer text for example). If you go further than 50 cm you will start to lose clarity rapidly.

Same applies for all values. If you don't believe then go and test it yourself. It always works the same. It's centimeters 100%.

I am going to also reply in your topic.

Offline johnlink

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Re: The Secret of Perfect Vision
« Reply #80 on: March 03, 2013, 03:07:47 PM »
If you read the 20/40 line you will see everything clear at 50 cm (computer text for example). If you go further than 50 cm you will start to lose clarity rapidly.

Same applies for all values. If you don't believe then go and test it yourself. It always works the same. It's centimeters 100%.
Steven, I understand and completely agree with what you've written in this post.

Offline Steven

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Re: The Secret of Perfect Vision
« Reply #81 on: May 10, 2013, 03:28:46 PM »
Tested my eyes again, 11 May 2013
I can see 20/40.

That means i finally got to -2 from -2.5.

I use a +2 that i try to use all the time.

What was the + power needed to reach 20/20 ?
What about 20/15, 20/10, 20/8 ?

Offline OtisBrown

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Re: The Secret of Perfect Vision
« Reply #82 on: May 10, 2013, 04:10:48 PM »
Dear Steven,

Subject: Congratulations.

Remarks:  After my vision was destroyed by 1) My own bad habits as a child and 2) A over-prescribed minus lens, I could only DREAM of reading this Snellen at 20/40 - naked eye.

There is a great power in being in personal control of your distant vision - and meeting and exceeding an OBJECTIVE REQUIREMENT.  This is what a good scientists will feel - when he is successful.  I hope you have a bright light on that Snellen and at 20 feet - for total CONSISTENCY.  20/40 passes all the DMV tests - in fact some States allow 20/50 vision.  I personally would not drive a car - until I saw and personally exceeded the 20/40 line.  I would emphasize that, in wearing the +2.0 for all close work - you are doing everything right.  That gets your "near" work, into the "distance" - with "pushing print" and reading at the self-determined, "just blur" point.

Now the difficult part.  To continue this success, and get to 20/30 and 20/25 - you must continue to do this.  From past experience, and much scientific data - it will take another nine months to get there.  I think it is highly worth it!  I would be proud to do it, as an organized scientific study.

The "plus power" required is limited to you reading at the "just blur" point.  Given your Snellen value (at this time) my estimate would be that the plus you have is correct.  Presuming that you begin to get close to 20/20 (refractive state = zero), you could then increase the "plus power" to +2.5 diopters, and maybe +2.75.  But that depends on you reaching 20/25 to 20/20 in the next six to nine months.  The really hard part of all this - is the dedication and time it takes to do it.  I can only encourage you to make this a "steady habit" and be patient.

Otis



Tested my eyes again, 11 May 2013
I can see 20/40.

That means i finally got to -2 from -2.5.

I use a +2 that i try to use all the time.

What was the + power needed to reach 20/20 ?
What about 20/15, 20/10, 20/8 ?

Offline OtisBrown

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Re: The Secret of Perfect Vision
« Reply #83 on: May 11, 2013, 05:58:23 AM »
Hi Steven,

Subject: Confirming your previous status of from -4.0 to -3.75 diopters (probably 20/200 on a Snellen chart).

This was one of Steven's first post, about Dec 2012.  I know how difficult is to get to OBJECTIVELY CONFIRMED (BY YOURSELF) 20/40 VISION. 

Almost EVERY OD will insist that is IMPOSSIBLE to get out of even -1.5 diotpters (about 20/60 on your Snellen).

Steven might be exceptional in his success in this amount of time.  I don't know.  I restrict myself to advocacy - at 20/60 or so on your Snellen.

My further remark is that LAST DIOPTER, from 20/40 to 20/20 - is the hardest and longest.  But I congratulate Steven on his obvious success - to pass all required DMV test.  I had not realized that at one point Steve had a -4.0 diopter prescription.

Otis


Hi Otis.

My current prescription is -3 left eye -3.75 right eye (which i feel is over prescription now).
I no longer have -4 in both eyes.

Right now i am reading this forum and the book.

You said i should go for a -2 to start with for long distance. I was thinking more of a -1.5.
I will order the next week at my local glass technician a pair of -1.5 for both eyes, since i am in Europe and the lenses i get from him are good quality from a Japanese firm.

Yes it will cost me more then the site you suggested but i can try everything here.

So:
1. I should use the -1.5 or -2 only for long distance and i must try to focus on things that are just outside my visual range ( a little blurry ). Correct ?

2. When using "push print" i use no glasses and when the image becomes too clear and my arm too short for the book i should use a +1, then +1.5, +2, +2.5 etc. as my vision improves.

3. Will using a very strong plus all day, no matter the activity, reverse my myopia much faster or will the eye just ignore the effort and stay the same ?

4. Will using a -1.5 or -2 while looking in the distance make my eyes more myopic or will my vision improve as long as i focus on semi-blurry spots ?

Thank you.

Offline Steven

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Re: The Secret of Perfect Vision
« Reply #84 on: May 12, 2013, 03:52:05 AM »
Thank you Otis.

I would say my success in such a short time is because :

a) I never used a minus lens after committing to improve my eyesight. ( only a half prescription, very rarely in urgent cases.)

b) I tried to use a +2 whenever i could.

Now, if i could have avoided all computer work and if i used 24/7 a plus lens i am sure i would have reached the targets even faster or i would have improved my vision even more.

Offline OtisBrown

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Re: The Secret of Perfect Vision
« Reply #85 on: May 12, 2013, 04:12:06 AM »
Hi Steven,
Subject: Now that you have verified 20/40 visual acuity on your Snellen...

Let me say the following:

1) When a person tells me he has -4.0 diopters of myopia - I simply do not know what to say.
2) But when he finds he can read the 20/60 line, then I will "talk".
3) I avoid making "claims" for the most part, but if a person has strong (long-term) resolve, and "gets the idea", then I think he can get out of 20/60 vision - objectively.
4) I love objective science, but I have a hard time "talking" to most people about this subject.  I do avoid "selling" anything - and make all this analysis available for free.
5) I wish to save the "next engineer" all the trouble I went through to learn the importance of "educated self-control", and self-measurement.
6) It is incredible to me that you got to 20/40 from -4.0 diopters, since Dec 2012.
7) You learned how to read your Snellen (brightly lit) and judge the "improvement" by hand-holding a minus lens.  That to me that  is "empowering", in the sense that you can estimate your refractive state - yourself. (Avoid involvement of an OD - who had NO INTEREST in any of this work.)
+++++
THE FUTURE?
I think that, since you "came back" from -4.0 diopters, the LAST one or two diopters will be the most difficult.  This is now, "all personal objective  judgment" on your part.
Leadership is *me* wearing a plus lens for all *my* close work, and self-measurement of my refractive status.  Leadership for *you* is doing the same thing.  If you can continue to wear the +2.0 for "just close work", for the next six to nine months, I think you will improve that "last diopter" - objectively.
I never judge my vision by "thinking" it has improved by "just looking".  No - I read my Snellen.  That is the only way.  The term, 20/20, does not mean all that much.  What you actually read will be from 20/25 to 20/15 - thus it is impossible for ANY OD TO SAY THIS OR DO THIS.  You must just check yourself.
As always, this is a very slow process.  You are the ONLY PERSON WHO "WINS".  So my request is that you continue to post your ideas, concepts, and your dogged persistence in wearing that plus for all computer and reading work that we are all forced to do in our "modern society".
Thanks for making yourself successful!
Otis



Thank you Otis.

I would say my success in such a short time is because :

a) I never used a minus lens after committing to improve my eyesight. ( only a half prescription, very rarely in urgent cases.)

b) I tried to use a +2 whenever i could.

Now, if i could have avoided all computer work and if i used 24/7 a plus lens i am sure i would have reached the targets even faster or i would have improved my vision even more.

Offline Steven

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Re: The Secret of Perfect Vision
« Reply #86 on: May 12, 2013, 11:19:48 AM »
Thank you again very much Otis.

You are my inspiration that made everything possible.

I am still working on my easy to understand guide, based on my experience in reversing the eye negative status.

I will post this guide as soon as i finish it.