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:
- Double vision with both eyes as a result of strabismus or other convergence issues
- 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. 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…
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 ). 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.