Double vision - recalibrating your visual system

The topic of double vision in relation to the EM method surfaces quite regularly. I too suffer from double vision from time to time. So I thought I’d share my method of working on it, in the hope that it might benefit other people who are also struggling with double vision.

There are of course two kinds of double vision:

  1. Double vision with both eyes as a result of strabismus or other convergence issues
  2. Double vision with a single eye as a result of (transient) astigmatism

I (fortunately) have no strabismus or convergence issues, so I have no experience dealing with those. This post is about the second kind: (transient) astigmatism.

First of all it’s important to check for yourself what your double vision is for both eyes separately, since these can be very different, as is the case with me. I find the easiest way to check this, is to look at clean white lines on a dark background from a distance of 3m or more, on a TV or computer monitor, while wearing my normalized glasses. Close or cover one eye and notice the doubling of the lines, the relative positions of the two images and the contrast of each image. This is not really about measuring the exact angle (I’ve never bothered with that), but for you to get a sense of which image comes from which eye. And what it is you need to work on.

In my case my left eye sometimes sees 2 images that diverge vertically (one below the other). This is consistent with the astigmatism correction I had is my original prescription glasses, which had a cylinder of -1.00 at an angle of 178°. At other times however the image is perfectly clear with no double vision whatsoever, which proves that this astigmatism is not something fixed or irreversible. It is interesting to note however that when I do experience double vision in my left eye, it is always at this approximate angle. The lower image is always fainter then the top image.

For my right eye on the other hand I’ve never had any astigmatism correction. This is my non-dominant eye however, and since I wear an equalized correction now, this eye is about 0.25 to 0.50 diopters more undercorrected and therefore always sees a slightly more blurry picture then the left one. The divergence in this eye is horizontal (side by side images), but the images lie closer together and have about the same amount of contrast.

So, knowing this I’ve developed the following training routine for dealing with double vision. I know there are apps and line drawings available to work on atigmatism, but I don’t like to use these methods, because they involve close-up vision, which we tend to get too much of already. So instead of using yet another app on your phone, consider going outside instead and use the many visual resources that are available out there. There really are plenty of things you can use to practice on, you just need to train yourself to be aware of your surroundings and look for challenging objects.

Now, we all know text signs are good for practicing active focus, but when it comes to double vision I found that thin straight lines with high contrast are the best thing. My favorites are power lines. These are perfect, because they’re long, relatively straight and have a high contrast against the sky. Besides, by changing your relative position you can look at them from different angles in your visual field, and find the optimal angle appropriate for you. That would be the angle at which the divergence of the two images is at its maximum. So for my left eye I look at horizontal power lines like these:

On days when I suffer from double vision my left eye will see an image like this:

Note the double images are relatively far apart, and the lower image is lighter (less distinct) then the top image.
So I close my right eye and look at these power lines. It’s been suggested you have to stare at them without blinking, but having studied the Bates Method before I found EM I really dislike staring and not blinking. :eyes: Fortunately this is not necessary at all. Instead of staring at one fixed point, I follow the power lines with my vision and also switch to a different cable now and them. And I blink naturally. Often it’s just after a blink that the two images suddenly merge and the power lines become perfectly crisp and clear. On a bad day this may take a minute or two to happen and it may only last briefly. When it doesn’t seem to work I, open my right eye (which has no problem with horizontal lines) and look at the power lines with both eyes for a while. Then I close the left eye and look at them with only the right eye, to teach my brain what they’re supposed to look like. Then I switch back to the left eye. I repeat this until the images fuse. My experience is that this exercise recalibrates the visual system and teaches the brain how to realign the diverging images. After doing this for a while the double vision lessens significantly or vanishes completely, for a while… On a good day however this isn’t necessary at all, and the power lines will simply pop into a single crystal clear image on the first attempt.

But we have two eyes, right? So I repeat the same procedure with my right eye, only instead of using horizontal power lines I position myself in such a way that the power lines run more or less vertically through my field of vision, like this:

My right eye will fairly consistently see an image like this:

Note that the double images are much closer together then is the case with my left eye. Also both images are approximately equally distinct. I find it much more difficult to fusing these images with the right eye. I attribute this to the fact that my right eye is more undercorrected. But after a few minutes of doing this, the images will eventually align.

So I often spend 5 to 10 minutes just looking at power lines. The people walking by probably think I’m completely crazy… :crazy_face:

I usually do all this while wearing my normalized glasses, but sometimes I will take them off and practice a bit with the naked eye. I find it absolutely astonishing how clear these power lines can sometimes become, even without wearing any correction (my normalized glasses are currently at -1.75).

But power lines like these are pretty rare where I live, since most of the cables are undergound here. So to get to these takes about half an hour, which is a nice walk on an off day, but too long for a walk during my lunch break on a work day. So on those days I have to make do with other things more close to home (yes I’m still working from home, and I love it :grin:). Here are a few pictures of some of my favorite practice spots:

The vertical lines on the railing are quite challenging for my right eye.

These fences are also perfect for training the right eye, but there are horizontal lines for training the left eye as well.

This pretty windmill is good for both eyes, since it has both vertical and horizontal lines.

Many nice horizontal lines on the railings. Perfect for my left eye. And there even some angled lines in that diamond shape at the center.


Thanks for this post, it’s really useful! Especially this part:

I will definitely try it, as I’m currently battling with double vision :slight_smile:

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Well, good luck. Let me know if this works for you.

This is such a top quality post, thank you! Coincidentally, I have almost the same astigmatism as you with respect to the left and right eye, and this post felt like it was tailor made for me, haha :smiley: I will definitely try out what you suggested (only my neighbourhood isn’t so pretty :’) )


I’m glad you find it helpful. Good luck with it, and let me know if it works for you.

0.00… WOW! Congratulations!
Yes, I also found Jake’s articles about the neon lights and the alarm clock very interesting. Unfortunately there are no neon signs near my place, so I haven’t had a chance to try that for myself. I did try the thing with the alarm clock though, but so far it hasn’t worked for me. But I guess this is something that’s only supposed to work with very low myopia (< -1.00). In my case there’s not just just double images when I look al the alarm clock but also a great amount of blur. I suppose it just doesn’t work under those conditions. But I definitely intend to try it again when my vision has improved sufficiently.

I can tell you that it already worked for me :slight_smile: Had double vision, tried only right (worse) eye, after a bit trying it got a bit better and then when I checked dual vision it was without any double vision :slight_smile:
I try to not forget to apply it :smiley:

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No I didn’t try it with differentials yet as I thought it’s supposed to be done with the naked eye. But yeah, it sounds logical, so I’ll give it a try. Thanks for the tip!

Great! I’m happy it worked for you. Just keep in mind it’s just a temporary effect. Your double vision will return after a while. But if you keep practicing a bit each time you’ve got the chance, it will become easier and quicker, and hopefully the effect will last longer.

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Here’s another picture I want to share:

It’s nothing special really. I use this balcony not so much to practice, but just to check how well my right eye is doing. This photo (made with my phone) makes the vertical spokes appear just as wide as the spaces between them, but that’s not what they’re like in reality. I guess the software of the phone tries very hard to increase the contrast and sharpen the image.

Anyway, with my right eye I usually cannot see the vertical spokes at all. It just appears as a uniform surface, whereas my left eye can easily distinguish them. So a while ago I decided I would reduce my normalized glasses when I could see the spokes with my right eye. I was wearing -2.00 at that time. Then of course I got a little impatient because with both eyes I could see almost perfectly and so I reduced my normalized to -1.75 six days ago. I told myself I would wear them for one day, just as an experiment. But I liked the experiment so much I decided to just keep wearing them, even though I’ve only been using the -2.00 glasses for 2 months.

Imagine my surprise today when I passes this spot, and I could make out the vertical spokes with my right eye, wearing my new -1.75 glasses! Granted it was a sunny day. But on other sunny days 1 or 2 weeks ago I could not see them even though I was wearing -2.00 glasses then.


Love the pics in this thread. I use my tag-in to determine what is going on with each eye alone, but admittedly I probably don’t spent enough time fusing with each eye on it’s own. I get the DV/ghosting in both eyes, usually one eye is over the other is under, though sometimes they switch and other times they match. Also at one point I had the side by side too, though that was during a DV phase over a year back now.
In addition to the power lines I use the siding on the neighbors houses. I do try to spend time fusing the images on each focal plane (normz, diffs, and no glasses) every day. And sometimes it will fuse without my thinking of it for a few minutes at a time. I am not sure it ever really goes away for a long period of time, more like goes further away (like way far) or is closer. As I mentioned in my thread that is why I am parking here until it is totally gone this time, as I have developed a habit of moving on when there is just the least bit in the far distance.
At any rate this thread has inspired me that maybe what I am missing is fusing each eye individually more often, so I will try working with that now too.


+1 for using the neighbours houses. Sometimes I wonder what would happen if they see me staring at their houses like crazy :smiley:


When I have (transient) astigmatism - at the last phase of a 0.25 sph improvement - it appears around 90 degrees. Fences are my friends, power lines, too, and there are a few old houses in the area with muntin / glazing bars in the windows. When I notice a part I can keep looking attentively until the rest becomes visible, too. I may rock, I may blink, I may take deep breaths to relax my shoulders and neck, etc., I may look very far and very near and then back to the original distance to achieve clarity.

Before I take my walk, however, I like to check the starting point with this pic. At the beginning, at -2D I had it printed on an A4 paper, now it is printed on an A5. It tells me if I have general “degradation of distance vision” due to too much close up time during work, or if I have the specific “around 90 degrees” weakness only. Actually the squares don’t look different anymore, but the circles with the vertical lines when placed between 1 and 2 meters may seem more blurry or less black than the other circles. This tells me what type of walk to take.


I like that bit. These are indeed some things that can be helpful.

The line drawings can indeed be useful to check your (transient) astigmatism. But for the bright white lines on a dark background about 3m distant make the double images most obvious. I have the media player function on my TV which highlights the selected file by placing a bright white box abound it’s thumbnail. The thumbnails themselves are often fairly dark. That’s just about perfect for me to examine my double vision… :face_with_monocle:

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