Astigmatism question related to AF

Hey all, I have something I’ve been wondering for a while and I would like some help from the community. We all know Active Focus is the stimulus to help with distance vision (improving sph). It seems like this is not talked about as often when I see people talking about improving astigmatism specifically. Does the same AF for Myopia distance vision also help with improving Astigmatic blur? I have read that for astigmatism, it helps to specifically stare at the text for a few minutes and be patient, and the double image can clear up more. In this case, is that the only stimulus for improving astigmatism? Does the normal AF where you try and clear up the blur at your blur horizon help astigmatism at all? Do you Specifically need to be doing the one where you stare at a piece of text for a few minutes patiently waiting for the double vision to clear up? do both help? Just looking for some clarification so I can better understand what’s best for helping my astigmatism.

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bump - I’m curious about this too

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In my experience, it’s a concentration on focus, but to find your specific challenge. For example, my cylinder is roughly 180, so I find horizontal lines most challenging. I seek to clear those as much as possible.

I note astigmatism is very sensitive to cylinder correction. You have to reduce some to improve, but too much is counterproductive. It’s an especially fine balance with cylinder.

You can read my journals for more details.

Good luck!

Kent

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Thanks, I think I have the same one, my Axis is 175 or pretty much 180. horizontal lines are hard for me too. I haven’t been using any astigmatism correction since my CYL is barely under 1 diopter. Do you think this is fine for improving astigmatic blur?

well according to Jake you could try not correcting it for close up/differentials, but for distance the effect of dropping it completely is greater and not advised

So when they say if it’s 1 diopter or less of CYL to just drop it, they are referring to mainly close up? This would make sense because it’s been hard for me to fully ignore the directional blur when doing outdoor distance AF.

yeap. any effect of light rays bending differently on different meridians would grow with distance so cyl is more important for distance vision

Looks like I’m probably going to have to get a new pair of normalized since I have no CYL correction in my correct one.

well it’s up to you, but my experience is I can lower sph more in the normalised if I just have my cyl to smooth out that directional blur which is somehow more annoying

Have you made reductions while doing that? That sounds interesting to me. Getting slightly off topic but I sometimes feel like I need a bit more blur challenge with my normalized so I have had thoughts about reducing my sph even more in my normalized, but the astigmatism makes it tricky, adding some cyl might make that idea manageable.

well I started off trying to reduce cyl and that didn’t work out (too much eye strain) so went back up and just reduced 0.25 cyl from full prescription immediately and also reduced sph. was able to keep reducing sph somewhat while still seeing OK as long as I kept my cyl. Ditching cyl power really makes the edges of letters rough while reducing sph increases the less-annoying kind of smooth blur if you know what I mean.
I know a lot of people inc. Jake say try to reduce prescription complexity by getting rid of that BAD cyl (sph is easier to handle) but you can also flip this argument on its head - it is EXACTLY BECAUSE the cyl is “bad” that you need it more - its lack is more drastically felt by the visual system. so yeah, I’d try that if I were you - give yourself your cyl back in your normalised with at most a small reduction compared to full prescription and you’ll be able to lower sph more - sph reductions are meant to be easier so you can get some practice on those then try to reduce cyl later. I don;t really know if my cyl reduction is a real reduction or just was a bit over-prescribed (opto tries to give you sharp night vision)

A bit worried to give myself full CYL because worried about it making my astigmatism worse, would it be ok to do a very slight CYL reduction and a more pronounced sph reduction?

I’m only talking about normalised. Why would it make your astigmatism worse if you’re just using it in the distance? For differentials you can reduce cyl more like I said. Plus I DID say do a small cyl reduction - you’re asking as if my previous post didn’t already contain exactly what you’re asking :smiley:

My bad, yea I meant normalized, i have low myopia so I don’t use differentials.

I have been reducing too aggressively both CYL and SPH, and it only made my vision (especially CYL) worse.
My cm measurements are now worse than they were 1 year ago.
So my suggestion is DONT REDUCE TOO MUCH
0.25 - 0.5D from full correcton is all you need to reduce.
If you want to reduce CYL, make sure you don’t reduce SPH at the same time, and that the SPH+CYL reduction is not more than 0.5D because then you might end up like me.

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well there you go - a second opinion that backs up what I’m saying

I’ve heard of too aggressive reduction stalling the improvement process, but vision actually getting worse? That’s somewhat worrying. So wearing more cyl than you need can create astigmatism, but so does wearing less than you need?

That is what happened to me. While SPH measurements improve, CYL measurements worsened. I was under prescribed by about 1D. Vision was terrible with lots of double vision.
Now i use a different approach of increasing sph while reducing cyl. I need to give it a few months to see how it goes, but i can already see better cyl numbers in my stronger eye.

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I tried dropping all cylinder for a few weeks, too. It was awful! So much blur, but I didn’t want to add -1.00D of sphere to compensate, because that just seemed wrong.

That experience did loosen up the cylinder a little bit, and I lost somewhere on the order of 0.75-1.00D of it. I’ve been working it down slowly ever since and getting good results.

Basically, I discovered that even though you can trade out 0.50D of cylinder for -0.25D of sphere, that’s exactly only one thing. 0.50D of cylinder is a lot, so a drop in 0.25D cyl is better than 0.50. A drop of 0.25D sphere and 0.25D cylinder is only 0.33D of Spherical Equivalence (SE), but it’s still a lot.

My strategy going forward is drop 0.25D of cylinder alone, get used to that, and then “ride” it for the next two-three spherical drops, then do another one. By this point I’ll be sub-1.00D sphere and -0.50D cylinder, and hopefully seeing well enough to only need glasses from time to time.

I think this is the 2nd research report (can’t find the 1st right now) that basically says -0.50D and less of astigmatism doesn’t really benefit from correction.

Astigmatism is a bear, and there’s no quick or easy way to work out of it, it complicates spherical reductions by adding correction complexity, and it confounds actual vision so it’s hard to tell where the improvements, if any, are coming from.

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