Author Topic: Online test for astigmatism  (Read 21214 times)

Offline johnlink

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Re: Online test for astigmatism
« Reply #15 on: March 17, 2013, 08:09:51 AM »
Hi John,

I have no interest in "astigmatism" - since I have 20/20.

John>  Otis, I am not suggesting you wear a lens to correct any astigmatism, but I am curious whether you have any. Would you please do the online test for which I posted the link

Otis> I have look at these charts before.  The are meaningless - in my opinion.  If I did do a CHECK - that I WOULD CONSIDER, I would use the OFFICIAL "Jackson Cross Cylinder" - which is the ONLY RIGHT WAY.

Otis> At this time - I do not have that instrument - but I will publish a YouTube on how to use it - if YOU WISH TO BE ACCURATE AND UNDERSTANDING OF HOW TO DO IT.


Otis, I look forward to reading your report of your test done with a Jackson Cross Cylinder and watching your video of how to perform the test. In the meantime would you please tell us, for each of your eyes, whether all the lines in the attached image appear to have the same darkness? It's a simple yes or no. Remember, only when you have the personal courage to check your own astigmatism - will you find out exactly where you stand.
« Last Edit: March 17, 2013, 08:53:38 AM by johnlink »

Offline OtisBrown

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Re: Online test for astigmatism
« Reply #16 on: March 17, 2013, 09:15:46 AM »
Hi John,

Here is the very cumberson and difficult "astigmatic test" - for your interest:

http://www.youtube.com/watch?v=_yB90F8zrow

I truly believe that if you took the SAME person to 10 different optometrists - you would get 10 DIFFERENT measurements for "Astigmatism".  But if you WISH to get an accurate measurement - then this is the ONLY way you can do it.

I have also examined your chart.  I see no "doubled" lines, or anything like that.

Our conversations do serve an excellent purpose.  If we were EVER to conduct a prevention study (from 20/60) for pilots - I am CERTAIN they would be asking your type of questions. 

Also - I will post the FAA requirements for astigmatism - in due course.  Thanks for your commentary - it is of value!

Hi John,

I have no interest in "astigmatism" - since I have 20/20.

John>  Otis, I am not suggesting you wear a lens to correct any astigmatism, but I am curious whether you have any. Would you please do the online test for which I posted the link

Otis> I have look at these charts before.  The are meaningless - in my opinion.  If I did do a CHECK - that I WOULD CONSIDER, I would use the OFFICIAL "Jackson Cross Cylinder" - which is the ONLY RIGHT WAY.

Otis> At this time - I do not have that instrument - but I will publish a YouTube on how to use it - if YOU WISH TO BE ACCURATE AND UNDERSTANDING OF HOW TO DO IT.


Otis, I look forward to reading your report of your test done with a Jackson Cross Cylinder and watching your video of how to perform the test. In the meantime would you please tell us, for each of your eyes, whether all the lines in the attached image appear to have the same darkness? It's a simple yes or no. Remember, only when you have the personal courage to check your own astigmatism - will you find out exactly where you stand.

Offline PhilippK

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Re: Online test for astigmatism
« Reply #17 on: March 17, 2013, 09:17:15 AM »
Hi Phillipp,

Thanks for your commentary.  Long-term near does in fact create BOTH negative status and astigmatism - as you report.  The fact that you can read at 40 cm with a +2.5 diopter lens.  I SUSPECT you are seriously over-prescribed.  If you continue to "work" this issue of "independence" - I suggest you get your own Snellen - and check for 20/60 vision.  

Further - I would "convert" your prescription to "spherical-equivalent" - if you order new glasses.  Just take the -2.25 and 1/2 the astig part.

Thus your OD will be -3.0 spherical, and the OD will be -3.0 diopters also.  (You can ignore the angle part of it.)

I also find that people are CONSISTENTLY over-prescribed by -1.0 to -1.5 diopters.  The fact that you can READ in bright light with a plus-lens - is suggestive of that truth.

Only when you have the personal courage to check your own Snellen - will you find out exactly where you stand.

Otis

Hi Otis

I find it painful to wear any amount of minus since I went cold turkey 7 months ago. I just checked my snellen outside after a few light blinks I can read all the letters on the 32ft line, although the letter V was really hard to recognize at first.
Dr. Colgate recommended to correct astigmatism, I wonder if should use a plus with undercorrected cyl while at the computer, or just continue naked eye?



What is the distance to your monitor? What is the distance at which you would be able to read it without it feeling like a challenge?

I'm still curious about this: Why do you say there is no change in your astigmatism? How have you measured it?

At 50cm from the monitor I can see clear enough to read , it doesn't get any clearer as I move in. Anything that isn't completely horizontal is always out of focus.

Offline OtisBrown

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Re: Online test for astigmatism
« Reply #18 on: March 17, 2013, 09:26:03 AM »
Hi Phillipp,
I know we EACH have our own private judgments about all these issues, about wearing a minus, about getting a "correction" for "astigmatism".  That is just perfectly normal.  I am personal friends with Dr. Stirling Colgate - and I don't recall him ever expressing an opinion on "astigmatism".  He use a plus on himself - and got back to 20/20.  Perhaps this is a different "Dr. Colgate".

Phillipp> Dr. Colgate recommended to correct astigmatism, I wonder if should use a plus with undercorrected cyl while at the computer, or just continue naked eye

Otis> This, of course must be your own judgment.  The fact that you can read the 32 foot line is excellent.  I would recommend you use the standard Snellen, and report you vision as 20/50, 20/40, 20/30 - just so we are taking about the same thing.

Otis> I work to the FAA standard - that only requires that I read the 20/20 line - and if I do that - there is no mention of astigmatism.  If a person feels more "comfortable" wearing a strong astigmatic lens - I have no objection to doing that - at all.


Hi Phillipp,

Thanks for your commentary.  Long-term near does in fact create BOTH negative status and astigmatism - as you report.  The fact that you can read at 40 cm with a +2.5 diopter lens.  I SUSPECT you are seriously over-prescribed.  If you continue to "work" this issue of "independence" - I suggest you get your own Snellen - and check for 20/60 vision.  

Further - I would "convert" your prescription to "spherical-equivalent" - if you order new glasses.  Just take the -2.25 and 1/2 the astig part.

Thus your OD will be -3.0 spherical, and the OD will be -3.0 diopters also.  (You can ignore the angle part of it.)

I also find that people are CONSISTENTLY over-prescribed by -1.0 to -1.5 diopters.  The fact that you can READ in bright light with a plus-lens - is suggestive of that truth.

Only when you have the personal courage to check your own Snellen - will you find out exactly where you stand.

Otis

Hi Otis

I find it painful to wear any amount of minus since I went cold turkey 7 months ago. I just checked my snellen outside after a few light blinks I can read all the letters on the 32ft line, although the letter V was really hard to recognize at first.
Dr. Colgate recommended to correct astigmatism, I wonder if should use a plus with undercorrected cyl while at the computer, or just continue naked eye?



What is the distance to your monitor? What is the distance at which you would be able to read it without it feeling like a challenge?

I'm still curious about this: Why do you say there is no change in your astigmatism? How have you measured it?

At 50cm from the monitor I can see clear enough to read , it doesn't get any clearer as I move in. Anything that isn't completely horizontal is always out of focus.

Offline PhilippK

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Re: Online test for astigmatism
« Reply #19 on: March 17, 2013, 09:27:13 AM »
My prescription was OD -2.25 x -1.5 x 90, OS -2.25 x -1.75 x 85.
The exercises were rotations and stretching which I still do everyday but don't devote much time to, and I am always pushing print to the point just before the astigmatism makes the text unreadable. Outdoors in sunshine I can wear a +2.5 and read close to 40cm but indoors on the computer it is challenging to read at 50cm naked eye, it would be nice if they made front-lit monitors where you could shine a strong light onto it.

What is the distance to your monitor? What is the distance at which you would be able to read it without it feeling like a challenge?

I'm still curious about this: Why do you say there is no change in your astigmatism? How have you measured it?

I haven't had any recent OD exams so maybe it has reduced slightly, it is just very annoying having two competing focuses in the same eye.
If anybody has eliminated their astigmatism from over -1 diopter I would love to hear how they did it.

Offline johnlink

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Re: Online test for astigmatism
« Reply #20 on: March 17, 2013, 09:27:44 AM »

I find it painful to wear any amount of minus since I went cold turkey 7 months ago. I just checked my snellen outside after a few light blinks I can read all the letters on the 32ft line, although the letter V was really hard to recognize at first.
Dr. Colgate recommended to correct astigmatism, I wonder if should use a plus with undercorrected cyl while at the computer, or just continue naked eye?

That sounds like a worthwhile idea to try. If you wore glasses that slightly under-corrected the astigmatism your print pushing might become more effective, reducing both the myopia and the astigmatism. You could get a pair of inexpensive glasses without an official prescription here: www.zennioptical.com

Quote
At 50cm from the monitor I can see clear enough to read , it doesn't get any clearer as I move in. Anything that isn't completely horizontal is always out of focus.

That's consistent with your axes of 90 and 85.
« Last Edit: March 17, 2013, 09:39:36 AM by johnlink »

Offline johnlink

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Re: Online test for astigmatism
« Reply #21 on: March 17, 2013, 09:36:19 AM »
I haven't had any recent OD exams so maybe it has reduced slightly, it is just very annoying having two competing focuses in the same eye.

I can imagine that it would be. Only my right eye is astigmatic so when I use both eyes naked the astigmatism is not so noticeable, but if both eyes were astigmatic I think it would be quite annoying.

Offline PhilippK

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Re: Online test for astigmatism
« Reply #22 on: March 17, 2013, 09:37:05 AM »
Otis,

Yes it is the same Dr. Stirling Colgate, here is a passage from "Dr. Colgate to 20/20" document on your older Myopiafree website

"           OTHER CAVEATS

     There is, of course, a continuing need to see an
ophthalmologists to check for all the other actual malfunctions of
the eye.  Fortunately, most of these are rare but they do happen.
One that is not quite so rare is astigmatism, perhaps 10% or
greater of the population.  Since, in the case of astigmatism,
there is no unique focus, the ciliary muscle is constantly hunting
for something that cannot be satisfied with the result that myopia
occurs even without a near point stress.  In this case you need to
correct the astigmatism, but also make sure that you have a
positive astigmatic correcting lens for near point work."

Offline OtisBrown

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Re: Online test for astigmatism
« Reply #23 on: March 17, 2013, 09:41:41 AM »
Hi Phillpp,
Subject:  I am very independent - in what I do and what I judge.
Regarding:  My own personal measurements of my refractive STATE (and astigmatism - if necessary.

I make all my own measurements.  The FAA has no astigmatic requirement - only that I read the 20/20 line. For that reason, I have no reason to measure astigmatism - at all.

I also find (in many ways) that we are over-prescribed.  You have a -3.0 diopter PRESCRIPTION.  Yet you can read with a plus on.  The -3 diopter prescription suggest that you can't see ANYTHING beyond 13 inches. Yes you are close to reading the 20/40 line - or better.  I would bet - if you checked - you would find out that you CAN read that line.  As a favor to me - could you check by using this chart.  Just "click" here:

http://www.smbs.buffalo.edu/oph/ped/IVAC/IVAC.html

And then on the word "Display" several times. The 20/60 line will come up.  Then back-off to 20 feet, and see if you can read the letters.  Get your friend to press "Display" for you.  See you can read 1/2 the letters correctly.  This will be a START for you.  Let us know!  I always like an "independent" person.

My prescription was OD -2.25 x -1.5 x 90, OS -2.25 x -1.75 x 85.
The exercises were rotations and stretching which I still do everyday but don't devote much time to, and I am always pushing print to the point just before the astigmatism makes the text unreadable. Outdoors in sunshine I can wear a +2.5 and read close to 40cm but indoors on the computer it is challenging to read at 50cm naked eye, it would be nice if they made front-lit monitors where you could shine a strong light onto it.

What is the distance to your monitor? What is the distance at which you would be able to read it without it feeling like a challenge?

I'm still curious about this: Why do you say there is no change in your astigmatism? How have you measured it?

I haven't had any recent OD exams so maybe it has reduced slightly, it is just very annoying having two competing focuses in the same eye.
If anybody has eliminated their astigmatism from over -1 diopter I would love to hear how they did it.

Offline johnlink

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Re: Online test for astigmatism
« Reply #24 on: March 17, 2013, 09:43:55 AM »
Otis,

Yes it is the same Dr. Stirling Colgate, here is a passage from "Dr. Colgate to 20/20" document on your older Myopiafree website

"           OTHER CAVEATS

     There is, of course, a continuing need to see an
ophthalmologists to check for all the other actual malfunctions of
the eye.  Fortunately, most of these are rare but they do happen.
One that is not quite so rare is astigmatism, perhaps 10% or
greater of the population.  Since, in the case of astigmatism,
there is no unique focus, the ciliary muscle is constantly hunting
for something that cannot be satisfied with the result that myopia
occurs even without a near point stress.  In this case you need to
correct the astigmatism, but also make sure that you have a
positive astigmatic correcting lens for near point work."

Using glasses to under-correct the astigmatism would be an application of Todd's idea that a little bit of blur, but not too much, is most effective for improvement. Philipp, I encourage you to give try it and let us know what happens!

Offline OtisBrown

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Re: Online test for astigmatism
« Reply #25 on: March 17, 2013, 09:49:16 AM »
Hi Phillipp,

Subject: I must draw a line - to determine if *I* am in control of my vision - or some OD is.

I love MDs and ODs. But they truly can not help me with these measurements.  I know it takes a very "independent" mind and person to truly do them.  I know that Stirling did not "bother" doing this - it was just so obvious to Stir that he HAD to wear the plus - that these "checks" were  not necessary for him.  But I find it VERY EXPENSIVE to go to an OD, and they don't have "time" for me - when I can and MUST do a better job myself.  Using two simple lenses, a -1 and a -1/2, I get accurate measurements.  Here is an example of how I do it - for your interest.

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

Offline johnlink

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Re: Online test for astigmatism
« Reply #26 on: March 17, 2013, 09:55:10 AM »
Hi Phillipp,

Subject: I must draw a line - to determine if *I* am in control of my vision - or some OD is.

I love MDs and ODs. But they truly can not help me with these measurements.  I know it takes a very "independent" mind and person to truly do them.  I know that Stirling did not "bother" doing this - it was just so obvious to Stir that he HAD to wear the plus - that these "checks" were  not necessary for him.  But I find it VERY EXPENSIVE to go to an OD, and they don't have "time" for me - when I can and MUST do a better job myself.  Using two simple lenses, a -1 and a -1/2, I get accurate measurements.  Here is an example of how I do it - for your interest.

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

Otis, while your video is interesting this thread is about astigmatism, so your post seems to be off topic. Besides, I believe Philipp already said that he is making his own measurements.

Offline OtisBrown

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Re: Online test for astigmatism
« Reply #27 on: March 17, 2013, 10:02:34 AM »
Hi Phillipp and John,
Subject: This thread is about how to make ASTIGMATIC MEASUREMENTS YOURSELF.
In that sense - you can not AVOID making BOTH these measurements yourself.  If I could do it - I would supply Phillipp with the required Cross Cylinder, and have him (and you) prescribed a cross-cylinder yourself.

Here is another video on how do exactly that. Please note that I DO NOT CONSIDER THIS A MEDICAL SUBJECT, AND THAT TAKING PERSONAL CONTROL OF THESE TWO MEASUREMENTS - IS NOT A MEDICAL SUBJECT.  But I do expect considerable expertise and responsibility to do it right - FOR MYSELF.

http://www.youtube.com/watch?v=ArtfTp72v64

John - as I mentioned - I would like to conduct an Engineering-Scientific study of true-prevention for pilots who ABSOLUTLY HAD TO GET TO NAKED EYE 20/20. I would consider this self-measurement (for knowledge) to be part of that study.

If you give the person the POWER TO MAKE THE MEASUREMENT - YOU REMOVE FROM THE PERSON - THE FEAR OF THE MEASURMENT. That is my philosophy in pure science.

Offline johnlink

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Re: Online test for astigmatism
« Reply #28 on: March 17, 2013, 10:03:36 AM »
I'm planning to do the practice I described in http://forum.gettingstronger.org/index.php/topic,468.msg3987.html#msg3987 with just my astigmatic right eye and also with both eyes simultaneously. Perhaps the left eye can help the right eye get rid of its astigmatism.

Offline johnlink

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Re: Online test for astigmatism
« Reply #29 on: March 17, 2013, 10:04:45 AM »
If you give the person the POWER TO MAKE THE MEASUREMENT - YOU REMOVE FROM THE PERSON - THE FEAR OF THE MEASURMENT. That is my philosophy in pure science.

I agree.