"Active Focus" on autorefractometer: astigmatism compensation?

AF (first) vs No AF (second) - open in new tab

Crystalline lens compensates cornea astigmatism up to 0.5 D (see E. Ruban) or even 1 D (J. Yee). Compensation is built on medial and lateral rectus muscle action, that is why there is no mean for lens to compensate for steeper horizontal corneal meridian (J. Yee).

Is so-called “Active Focus” (outside EndMyopia science/program there is no such thing at least named so) a compensation for physiological astigmatism, and the smaller amount of latter is, the bigger amount of former present?

If there is a ciliary spasm / oblique muscles spasm / slack suspensory ligaments, then lens cannot compensate basically any amount of astigmatism, that’s why Ortho C “treats” astigmatism. It has no effect on reducing physiological astigmatism afaik.

Mine compensated roughly 0.5 after Atropine or other mydriatic drops instillation.
But in 2011, lens indeed compensated 0.75 to 1 of cornea astigmatism.
I know that because of manuscript K readings I almost read due to text watered out significantly from time, right flat K was the same but steep K was 1 D less, resulting in -1.0x180 astigmatism.

@Ursa, your left eye astigmatism is basically against the rule (60-120 minus), maybe that’s why lens cannot compensate it.

@Dlskidmore, maybe you have wandering axis of astigmatism because of the same reason: when lens compensates slight astigmatism from cornea, there could be a random axis every time (see first autorefractometer). But, stupid optometrists just gave you (and intended to give me back in 2011) unnecessary cylinder correction which now became permanent in you. From your experience I could suppose that normal lens function cannot be altered from extreme amount of myopia or axial elongation. Maybe you will measure your axial length, let we know how long your eyes are to compare with other eyes?

The other possible argument why extrinsic muscles cause myopia, hyperopia and astigmatism, ciliary spasm:
Did you look at high axial hyperopes’ refractions?

For example, I have found roughly this somewhere that I can’t found on medical forum anymore:
High hyperopic child
+5.00/+2.00x180

Very unlikely that is the lens astigmatism because of its graveness.
180+ (axis 90-) is the opposite to average myopic astigmatism 180-, so it’s against the rule.

So, as I can guess, in hyperopia, there is a hierarchy of tonus SR, IR > LR, MR > IO, SO. The first have the most isotonic concentric tonus, the last have the most isometric.

In myopia, isotonic SO, IO > MR, LR > isometric SR, IR.

https://europepmc.org/article/PMC/5404965

Very complicated for my brain, maybe @Ursa can swim in.

I can’t check whether I have AF with the fullest cylinder correction (so lens will not be busy to compensate astigmatism instead of doing AF), because I bought too many contact lenses already. Yes, the image feels more comfortable, but I don’t remember any AF using last lenses with fullest most suitable cylinder correction.

Maybe someone on this forum who don’t have AF can check this.

Thanks for posting this. As I have oblique astigmatism, I am very interested in this, but I will have to read it more carefully to wrap by brain around it.

Later: After a brave attempt, I must concede that I cannot wrap my brain around it, and it does not seem to have any real practical implications which would be of any use to us, so i have given up.

I tried to remove corneal astigmatism by pressing on the outer side of cornea through eyelid, astigmatism removes completely when pressing so to the right extent.

I checked right eye when doing so, there is no visible astigmatism. Haven’t seen any AF, but pressing and blinking simultaneously is unreliable, so it might be too much stress.

Clear distinguishing between the types of astigmatism doesn’t do job well imo.
That is de jure distinguishing widely accepted by optometrists, but the nature can have slightly other language.
I’d say you have against the rule astigmatism even if it have 120-125 axis.

About 50 degree astigmatism, that could be absent from starting, as I say, despite my cornea was WTR, lens compensation for that was oblique sometimes. Optometrist gave you that correction and it became permanent. There is another post by other person wrote the same: lens compensates for uneven cornea up to 0.5 D. But, it seems also to 1 D with the rule or (less diopters) oblique. Compensation for ATR is not possible in my experience as well as J. Yee claim.

I have done a bit of gentle corneal pressure throuhg an eyelid - with amazing effects that don’t last. I don’t think this is the way to go. I still have a hard time fixing on an axis of astigmatism for the left eye, but it is no longer important, as I wear no correction. In that eye lines become wavy after a certain distance, with a constant attempt to straighten them by the visual machinery, making the lines dance. Interesting but not very useful. My right eye has a constant axis of astimatism at 50, and no wavy lines. No wonder my visual cortex favours the right eye. :grinning:

I think astigmatism should be easier to solve than myopia.
Hannie, have you tried eye exercises? Eye exercises seem to allow a better visual cortex caliberation with eyes and removing astigmatic aberration.

Thanks people for responding, but I already said what I should be to say :slight_smile:

I did an endless amount of them while trying the Bates method. They did improve my vision, but I have no idea by how much, as I had not learned to measure my eyes. I gave up on them as this became tedious, and my gains were lost.

I decided to try the EM method without any exercises, to find out if this worked. It has. I found out that it also worked without having to wear glasses, and with considerable blur tolerance, and that has also worked. The basis of the method is providing a stimulus to which the visual system responds. That seems to be enough for me, as my considerable improvement in the space of 1 year has shown.

For as long as my left eye continues to improve, no matter how slowly, I will not add anything, neither eye exercises nor patching, even if such things would speed it up. For me this is a scientific experiment to show that these are not required. I also became quite allergic to such things in my two attempts with the Bates method. The only useful thing I have held over from the Bates philosophy was to wear my glasses as little as possible, as I did for the 30 years before starting EM last year. My way of life allowed me to get away with this.

I see pretty well on the strength of my right eye alone, so there is no rush.

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Which eye exercises did you try? Just curious… :thinking:

All the Bates Method ones, and I can’t remember them offhand. You can easily find them online.

Hmm… there seem to be different versions online! :confused: How much time did one session take on avg? And you practiced it everyday?

Sorry, can’t remember. This was about 20 years ago. :upside_down_face:

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20 years ago I remember fine. Last week is another story.

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Not there yet - and may the Fates forbid it

EM serves a double purpose for me - all the research on vision is a part of my strategy to stave off dementia. I am only 75, but it is not too early to start on this.

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Maybe you can also try these to stave off dementia:

  1. Sudoku
  2. word puzzles
  3. chess
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I prefer bridge to chess, never had much fun with sudoku, like crossword puzzles well enough, but prefer scrabble. I need a little more challenge than this, like online courses and challenging lectures on subjects I am not too familiar with. I have been doing this for about 15 years. Learning a new language would do the job nicely, but the one that would be the most useful to me would be Tibetan, and that is a daunting challenge on account of the script that I would have to master first. I do want to be able to enjoy the new skills and information I am learning, rather than doing it just for the sake of keeping me firing on all neurons. :wink:

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