Dizzy after first differentials for 6 weeks... should I get second reduction?

Hi folks!

I had been using my first pair of differentials for around 6 weeks already, without any problems whatsoever, my eyes having adapted to it for close-up since day one so happily.

But just around the same time that I had planned to order my first pair of normalized, whenever I use my differentials I get ultra dizzy (up to the point of wanting to vomit, etc) and spending the rest of the day feeling sick and I’m wondering why this is happening now and not before? I have made the test a few days now and it is indeed the differentials causing this.

I am aware from reading the blog posts and other users, that the first differential pair is supposed to be used for approx. 6 weeks and later, when ordering the second differentials pair also order the first normalized. Is this what is happening? Is my dizziness the sign that it is time to reduce again?

The funny thing is, I have seen a small improvement of my centimetre measurements after starting to use them for the last 6 weeks (around 1-2cm). It is a small improvement but it made me so happy, and I also realized these days that for closeup work, I can see so much better without glasses than before the differentials. (I noticed this because as I felt dizzy, I stopped using the diffs and went no-glasses instead for closeup). I have avoided the computer except to post this.

My original prescription was OS -5.50 OD -5.50 cyl -1.25; and the diffs I have been using are OS -4 OD -4 cyl -1.25 til now.

So in conclusion, I’m a bit stumped with what to do. Is my dizziness a sign to pick my second differentials? Is it okay to buy my first normalized anyway?

I hope anybody can shed any light in this, and if there is any blog post I might have missed about this topic, I’d love to know. If anybody has also experienced this i’d love to know about it, as I’m curious.



If you see everything perfectly clear out of them maybe they are now too strong, not sure why else you would suddenly have a problem

This doesn’t sound like a normal symptom of using weaker glasses. TBH, I’m fumbling in the dark here, but I’ll try throwing in some thoughts.

It could be that your eyes relaxed enough in the first weeks to make the jump between your old glasses and the differentials quite big. In this case, getting normalized as planned seems like a sensible choice.

Reducing the differentials is a strange idea. You didn’t get dizzy when you were using much stronger glasses on the computer, so why should going even lower right after this huge 1.5 dpt jump solve the issue? If the differentials would be causing this by being too strong, your distance glasses should be unbearable.

Some people get seasick, or sick from closing eyes in cars, riding roller-coasters, using VR, etc. Did you ever have these kinds of sickness, and does the current one feel similar?

Do you turn your head a lot with your differentials on? Maybe have a look at your visual scanning habits; normally, your eyes would jump around, and your head only follows slowly and minimally. If you swing your head around a lot with strong spherical lenses on, the displacement can be confusing to the visual system.

I’m wondering if the brain somehow picked up on the differences in displacement between the glasses, which can be strong at 1.5 dpt difference and possibly different frame geometry; this could trigger a sickness aimed at psychedelic poisons, because this looks to the brain like the sense of balance/gravity is out of sync with visual movement.


Thus is a real thing. I’ve had it. Some people simply cannot tolerate certain lens shapes/sizes. The thing is, I’ve always had those issues from day one with glasses, not starting after weeks.


One potential cause for feeling dizzy and nauseous (yes up to the point of almost vomiting) is neck and/or shoulder tension, too weak glasses leading to bad posture being one possible root cause. Been there.


Hi Varakari,

Thanks for your ideas. The thing is, my distance glasses are also unbearable. I did get dizzy with them and still do if I use them for closeup - I can only tolerate them for very large distance vision, and even so, there’s times they do make me feel dizzy.

In fact, it also happened with my old glasses and my optometrist agreed to reduce my spherical (I used to have - 6.50 sph years ago and have reduced twice ever since!), all of this before knowing about the endmyopia method, and my symptoms began to subside.

Over the years I have seen that whenever these things happen to me, it is because my glasses have become too strong. And I adapted to my diffs so quickly that even now I feel they are strong, just as another commenter suggested here.

That’s why i’m wondering whether if I should try buying my first normalized and a slightly weaker differential to see what happens… But I wanted to see first if anybody else had any similar experiences to me, because I also find strange that this is happening now and not since day one.

I’m visiting my optometrist again probably soon, if this continues to happen. But I do think it’s that my prescriptions are too strong, because I find active focus so easy on my diffs and everything clears up so quick, shame it’s making me dizzy weeks later :frowning: because I don’t get dizzy with other things.

I really am thinking how to proceed yet.


This is interesting :thinking: my differentials have the same mesasurements and frame as my distance glasses, though. So not sure about that still.

You should know from measurements whether glasses are too strong. What’s your focus range with the differentials, and how does it compare to the usual work distance you use them for?

Did you maybe take off your glasses more often lately, and got used to the lack of distortions, so that the glasses suddenly feel strange? I still can’t help but think that your symptoms remind of motion sickness, and changes in the peripheral distortions from glasses could plausibly cause this.


Another possibility but not as likely, is poorly made lenses.

1 Like

According to my measurements after my improvement with them, I should be using around -4.50 for distance (normalized) hence that explains my former question too (as I still have my original prescription for distance).

My focus range with the diffs has been 60-70cm on the computer, I work both as a psychologist (don’t need them for that fortunately) and as an artist (I paint). For the latter, I did use them for a similar range.

My diffs do feel strange sometimes as if I found them too strong already, but I haven’t been taking them off more than usual so no getting used to lack of distortions.

My diffs were bought on Zenni, so I don’t think it’s the quality. I seriously don’t know what to do, because I wouldn’t like to lose my progress up to now, and I sometimes feel disheartened and want to give up :frowning: It feels so complicated right now… and I’m afraid of messing up my vision and its focal planes for the worse.

What came to my mind first when reading your first post was the cylinder correction in your differentials. Maybe your eyes have already relaxed so much that you now feel this discomfort at a close distance?
Have you seen this blog post for example?:

Your cylinder is even lower…I don´t have a cylinder in my glasses, so I can´t say from my experience, that just was my first thought.

1 Like

If I understand this correctly, I could assume 67 cm focus range with your sph -4, cyl -1.25 glasses, which corresponds to a refractive state to the horizon of -5.5 sph, plus the cylinder – which is what you use for distance. If this is correct, your distance glasses might have become an overcorrection.

However, I don’t understand how you come to the conclusion of using -4.5 for distance; that sounds like too large a jump. If the above is correct, they’d only give you 1 m focus range, which is low for distance training.

My best idea, if I imagine myself in your shoes, is still to reduce the distance glasses’ spherical a little, avoid wild head movements with the differentials on, and have a look whether you can get used to that new combination over a few weeks. (As usual, please don’t read this as some form of prescription. I’m just throwing ideas based on your story.)

Also, @FMR has added a good warning: maybe have the glasses checked. Sometimes there’s a manufacturing error, and that can make things wrong in all kinds of ways. I’ve been there, even with really expensive glasses.

Hi Varakari,

I came to that conclusion because using Jake’s myopia calculator, with 22cm until the edge of blur, my distance correction should match -4.50. When I started the program, I had 16-17cm measurements. I also don’t make wild head movements with diffs on, and I always ensured not to anyway.
I know your ideas are not meant to be taken as any kind of prescription, don’t worry. :slight_smile: But your ideas do help me reflect on what could be best for me, as that of course is only my responsibility and choice.

As @eagle-eyes suggested, I’m beginning to think it’s the cylinder too, because I’m starting to feel uncomfortable with my distance glasses’ cylinder now too (it has happened to me in the past, and was confirmed that was the issue with an old prescription of mine years ago) and in close-up, it feels even worse, whether they be distance or differentials.

@eagle-eyes, thanks for your input. I didn’t know about that blog post and I’ll study it these days!

My plan is to go to the optometrist soon, see what comes up, and order some normalized and new diffs with less cylinder too, working from the result given then. It’s what makes more sense to me right now. Because despite that dizziness I can obviously see my eyesight has improved since I started the program and my original prescription is being a nuisance already.


You are welcome, well, there are different approaches with those cylinders :face_with_raised_eyebrow:, just came across your other topic regarding cylinder in differentials. You will find out what works best for you…

And great progress so far, from 16-17cm to 22cm is really awesome!


This is an old thread, how are your eyes doing? What did you finally decide to do, why, and how did it turn out? I am curious :innocent:

1 Like

I’m curious to know it too

1 Like

Hi! Sorry for replying quite late. Life got in the way, plus the quarantine stuff :slight_smile:

I am glad to say that IT WAS the cylinder messing me up, and it was that mismatch between my sph correction and cyl correction what was making me feel poorly.

As my eyes were feeling strained at that point, I visited the optometrist as I was planning to (that was during March 2019). He was extremely baffled when he realized I didn’t need the -1.25 cyl I used to any longer :smile: I currently use only -0.5 cyl I wish to ditch sometime in the future as I continue practising.
So he relented, as he tested me with his Snellen chart and had to admit that my sight had improved. So he gave me a prescription of:

OD: -5.25 sph, -0.5 cyl
OS: -5 sph.

By the way, my advice - always ALWAYS ask for a Snellen chart test, like you practise at home as Jake has spoken about before. Some optometrists have machines that supposedly accurately measure your sph and cyl, in total room darkness, might I add. He used the Snellen test on me because I repeatedly insisted and he was reluctant to, and finally acquiesced. I don’t want a machine to randomly decide my prescription for me.

Fast forward to this year. I went back last month, and still hold the same prescription as last year :slight_smile:

OD: -5.25 sph, -0.5 cyl
OS: -5 sph.

As you can see, my sph might not have changed much, but it has decreased (compared to my original post on this thread) and the cyl is almost gone. I’m happy because slow and steady wins the race. No rush.
I have managed to slowly normalize both eyes with that, and that’s HUGE for me per se. Years ago both eyes had very different prescriptions.

I stopped using diffs for quite some time (around march 2019) to allow my eyesight some stability after all that uncomfortable dizziness. Now that I’ve been stable for months I will calculate my new diffs sometime soon.

Quarantine ensued so I had all of this on hold now, but not for long. Time to try some new gains :smiley:

I hope life is treating all of you well despite the coronavirus crisis.