Author Topic: Monocular Double Vision & Astigmatism--Connection?  (Read 2602 times)

Offline warnbd

  • Newbie
  • *
  • Posts: 40
Monocular Double Vision & Astigmatism--Connection?
« on: October 03, 2014, 11:39:09 AM »
I have been making steady progress since Jan and recently have run into some challenges with my 4th set of “therapy” glasses.  I am now getting the double vision ghosting in each eye when using my distance under-corrected glasses.  But when using my near work “plus” glasses, this is not a problem (except slightly when eyes are tired).  I have kept the cylinder prescription the same for my reading and distance glasses, but now questioning that decision. 

When I go back to my 2nd set of therapy glasses, the ghosting goes away (95%).  These had +2.0 cyl left, +1.0 cyl right.  Current glasses have +1.0 cyl and 0 cyl.  My hypothesis is that the cylinder values may have to be different for distance and reading glasses.  My rate of spherical improvement is faster than my astigmatism improvement rate.  I thought I could keep incrementing my cylinder down, and avoid the ghosting.  My choice is to try to ignore the ghost images (like Todd B. with the power lines) or put some more cylinder back on distance glasses.  I think what Todd experienced was, as his spherical myopic component improved, his remaining astigmatic error was revealed as the ghost images at distance (power lines, etc.).  Fortunately, over time the ghosting faded away.  I have been using the astigmatic mirror or spoke diagram at D2/D1 to make judgements for cylinder levels.  Apparently, less cylinder is needed when doing near visual work. 

Questions for the forum:

1.   Does it make sense that different cylinder levels are needed for reading and distance glasses?  If so, what is the physics explanation for this?
2.   Is my hypothesis reasonable that monocular double vision is residual uncorrected astigmatism?
3.   How long does it take for this double vision effect to be mostly gone?
4.   Why when eyes are more fatigued, does the double vision get worse (greater shift, darkness of ghost) if astigmatism is   only corneal shape?  Maybe ciliary and occular muscles contribute to astigmatism?
« Last Edit: October 03, 2014, 11:51:11 AM by warnbd »

Offline Alex_Myopic

  • Sr. Member
  • ****
  • Posts: 426
Re: Monocular Double Vision & Astigmatism--Connection?
« Reply #1 on: October 04, 2014, 08:20:50 AM »
Is there a specific reason you associate double vision with astigmatism only?

With diplopia someone is positive to the astigmatic wheel test. Maybe all the meridians of the eyeball don't heal with the same rate so a lot of people in visual rehabilitation after some diopters improvement they face diplopia especially when looking with one eye only.

In Dr Robert-Michael Kaplan's book there is an exercise called the swing ball and he suggests the axis of swinging should be vertical to the axis of astigmatism but I haven't been able to find this exercise. I have posted the astigmatic mirror exercise before and my variation of it for diplopia.
« Last Edit: October 04, 2014, 09:19:51 AM by Alex_Myopic »

Offline Myoctim

  • Jr. Member
  • **
  • Posts: 56
Re: Monocular Double Vision & Astigmatism--Connection?
« Reply #2 on: October 04, 2014, 09:16:09 AM »


Questions for the forum:

1.   Does it make sense that different cylinder levels are needed for reading and distance glasses?  If so, what is the physics explanation for this?

Hi warnbd,

the optical physics about that difference shouldn't be hard to understand:

When reading, as a myope you easily can approach to the "circle of least confusion" distance which is equal to a full spherical equivalent (SE) prescription.
For doing the same at far you would need to be emmetropic or hyperopic in sphere to focuse at that intermediate meridian.


BTW, although I highly respect Mr. Otis Brown I personally can't agree with his (a bit biased) recommodation for ALWAYS using the SE because it only caught me on a plateau.

After searching for emmetropization and astigmatism it showed there are several papers suggesting while there always being a direct compensation for spherical errors the response on astigmatic aberrations seems to be different.

Particulary in primate studies it was found emmetropization only picking one of the 2 astigmatic principal meridians.

Because the SE works by increasingly overcorrecting half of the meridians it raises the question what if hormesis would pick the "wrong SE' overcorrected" ones.
                                                                                                       

                                                                           



Offline OtisBrown

  • Hero Member
  • *****
  • Posts: 1762
Re: Monocular Double Vision & Astigmatism--Connection?
« Reply #3 on: October 04, 2014, 09:31:43 AM »
Hi Myo,

Otis> Thanks for your kind commentary.  I respect medical people in so many ways.  Except for the issue of self-prevention.  Some of them know that it would be wise, but realize that most of us will not "stand for" prescribing a plus for prevention.  I understand that issue and respect it.  But that means, if I want prevention - I will have to do all of the measurements and judgments myself.  In that sense, I am indeed biased.  But I am thinking of full empowerment of the person himself, who does not want to get into intricate measurements using a Jackson-Cylinder, and complicated measurement system.  (That are very time-consuming, and in my judgment, not very accurate or effective.)

Myo> BTW, although I highly respect Mr. Otis Brown I personally can't agree with his (a bit biased) recommodation for ALWAYS using the SE because it only caught me on a plateau.

Otis> I mean use a SE for your measurements of refractive status.  When I say this, I am thinking that the person wants to get rid of wearing any lens for distance.  But that means, at self-measured 20/50 to 20/60, he will have to get his own "reduced" lens from Zennioptical (and save arguements with an OD about what you are doing).

Otis>  My feeling about mild astigmatism is this.  All normal eyes have a slight amount of it.  It is a totally normal situation.  It is true that with ONE EYE, you can probably measure -1.0 diopters of it.  But that ignores the fact that we look at objects with BOTH EYES OPENS.

Otis> The brain is a sophisticated system.  The two images are over-laid, and the imperfections are cancelled out.  Therfore, there is no need to, "correct" for a mild amount of it - even if you measure it.  My bias is to establish (from 20/50) I can read the 20/20 line THOUGH a -1.25 diopter spherical lens.  I do this for several reasons.

Otis> If I can read 20/20, then my eyes have no medical problem at all. There are too many people who believe that a lens is a medical device, for a medical problem.  I deny this completely.  But I do recommend you personally know how to make this check.

Otis>  I can do this check with two spherical minus lenses, of -1/2 and -1 diopter.  (I can create -1.5 diopter by putting the two lenses together.)

Otis> Only if I could not get 20/20 though a minus lens, would I even consider checking for astigmatism.  But, yes, the desire is for simplicity, and "do measurements yourself", is part of my personal bias on this subject.

Otis> I know that each of us must choose his own path to 20/40, and then to 20/20.  I only express this idea as I have 20/20, and type this with no glasses on.  (But I do wear them to prevent myself from going negative again.)




Questions for the forum:

1.   Does it make sense that different cylinder levels are needed for reading and distance glasses?  If so, what is the physics explanation for this?

Hi warnbd,

the optical physics about that difference shouldn't be hard to understand:

When reading, as a myope you easily can approach to the "circle of least confusion" distance which is equal to a full spherical equivalent (SE) prescription.
For doing the same at far you would need to be emmetropic or hyperopic in sphere to focuse at that intermediate meridian.


BTW, although I highly respect Mr. Otis Brown I personally can't agree with his (a bit biased) recommodation for ALWAYS using the SE because it only caught me on a plateau.

After searching for emmetropization and astigmatism it showed there are several papers suggesting while there always being a direct compensation for spherical errors the response on astigmatic aberrations seems to be different.

Particulary in primate studies it was found emmetropization only picking one of the 2 astigmatic principal meridians.

Because the SE works by increasingly overcorrecting half of the meridians it raises the question what if hormesis would pick the "wrong SE' overcorrected" ones.
                                                                                                       

                                                                           
« Last Edit: October 04, 2014, 12:36:08 PM by OtisBrown »

Offline Myoctim

  • Jr. Member
  • **
  • Posts: 56
Re: Monocular Double Vision & Astigmatism--Connection?
« Reply #4 on: October 09, 2014, 04:39:00 AM »
Otis> I mean use a SE for your measurements of refractive status.  When I say this, I am thinking that the person wants to get rid of wearing any lens for distance.  But that means, at self-measured 20/50 to 20/60, he will have to get his own "reduced" lens from Zennioptical (and save arguements with an OD about what you are doing).

Hi Otis,


THX for your explanation.

When looking back to my prerehab time I also never cared about astigmatism because I even didn't know about having some minor one.
So I agree in the case of some minor astigmatism below about 1D.

But after my horizontal meridian recovered more rapidly compared to my vertical it resulted in that 1.25 cyl prescription but giving me an amazing 20/15 vision.

Being scared about that astigmatism would further progress when using a full time cyl. prescription I mostly used a -1.75D SE undercorrection which gave me 20/30 day light vision (except for driving because night vision was pretty poor).

But there was no further recovery for all that time I used that SE correction.

So I guess in my case hormesis did pick the wrong meridian  :-(

Offline Alex_Myopic

  • Sr. Member
  • ****
  • Posts: 426
Re: Monocular Double Vision & Astigmatism--Connection?
« Reply #5 on: March 20, 2018, 04:03:42 PM »
About 3,5 years later and I found this topic extremely interesting to me. After years of rehab I found myself in this condition too (monocular double vision) although I started with 0 astigmatism and -2,25D myopia.

 Today after self-experimenting with my older spherical lenses of various degree I found that a spherical equivalent can make my diplopia disappear 100% when it is most prominent, while looking at the astigmatic wheel! The more I increased the diopters the closer the two ghosting lines where getting and more sharp until they became one at about  -0,5D!

I'd like to thank Mr Otis Brown for learning me the spherical equivalent of a myopic prescription with astigmatism.
I got to a point that gave up plus lenses because my weaker eye did't improve although I patched. So I thought that with this difference in my eyes I could get my sharp eye sharper while wearing plus lenses with the same prescription.  Now I could buy plus glasses taking into account the SE (spherical equivalent) in my weaker eye.

I've been into a plateau for almost 1,5 years and I find this way might be a breakthrough. I can even wear a 0 diopters in my left and -0.5D in my eye with diplopia while reading subtitles in the tv or at night when myopia is more apparent.

I feel my right eye is becoming too lazy and adapted to blur and diplopia not taking account this difference and SE make matters more simple especially if I want another pair of plus lenses for too close distance (reading a book) and another for my computer screen. -0.25D is a small difference between the two eyes and might be due to a dominant eye but -0.5D difference due to diplopia means about -1 cylinder difference so one must take it into account even for plus reading glasses, because that way we read at the edge of blur so diplopia is apparent even then. Reading with plus lenses is not like "reading something in small distance so I can neglect even medium astigmatism". If I close my dominant eye while reading with my current plus glasses the weaker eye cannot make out the letters.

So in the question 1 in the first post my answear is yes because reading with plus lenses is not a close distance activity in relaton to the image perceived in the eye. Spherical equivalent clears the problem. Some posted that undercorrected cylinders are best in order to aim at the problematic meridians more correctly but that would make matters more complicated and expensive.

In question number 4 I've noticed the same thing to me too!


A video of Jake telling people with low myopia to wear undercorrected glasses at night for the eyes in order not to adapt to blur and be at a plateau even if not wearing minus at all. He doesn't talk in this video about the refractive ratio in the two eyes.
https://www.youtube.com/watch?v=OYNwz_gcNXQ&t=40s
« Last Edit: March 20, 2018, 04:19:36 PM by Alex_Myopic »