Hi Martin! That is an interesting theory to explain some part of the problem but not all of it. I suspect there's something more.
I have severe pain from new smartphones and I have an excellent binocular vision, when I look at the broke string I see image from both eyes and a correct focus point.
Smartphones break my vergence immediately (within seconds), by some light effect, but not flicker. After usage I am not able to focus far: eyes cant diverge enough. Additionally I percieve the screen as bright when it is visibly dull, and my retina photoreceptors are tired or damaged after screen usage.
There are more people like me among those who do not tolerate only modern smartphones or some modern smartphones. The intensity of symptoms vary.
I am trying to research that particular effect and created a light/vergence thread here.

    Mrak0020 This is also an interesting theory. I suspect that the new lighting breaks vergence even in healthy people, it just takes longer time for them. My proof of this is that more people that I personally know now start to complain about feeling like starting to see double and unable to hold single point with both eyes when they spend too much time working on new displays.

    What you describe still sounds to me like BVD (convergence excess), maybe the brock string is not proper tool to diagnose your specific case. Maybe you are able to compensate the issue when using brock string.

    The bottom line then would be - new display rendering and LEDs break eye vergence. When you have BVD, it happens a lot faster, as your eye vergence is already impaired.

        martin What you describe still sounds to me like BVD (convergence excess

        I believe that is not the case based on the evidence:

        1. I have never had any problems with anything and I can focus anywhere I look in less than a second.
        2. Looking at the screen breaks my vergence immediately and severely. I feel excuriating muscle pain the very moment I look at screen and I can't focus anywhere far immediately after. I feel like when I look far my eyes meet some invisible wall. That wall is an impossibility to diverge my eyes. So it is the phone that creates a convergence excess and not a convergence excess that causes my inability to use the phone.
        3. Image from any single eye of mine (with my second eye closed), especially a dominant one, feels like everything changed positions in space. I literally see this effect, because it is so unusual for me.
        4. This effect comes together with subjective feeling of super extra bright screen. A lot of people on the tech forums either feel only this symptom or this symptom together with convergence problem. We call it "feels like you look at a welding". This feeling is not only not a visual illusion but an indicator of some fotoreceptors overuse, cause they sometimes cause impossible light sensitivity.

        I checked my screen for rendering and flicker and can say that it is not a cause.

        So probably in some cases it is a binocular vision problems that cause the intolerance to usual, safe light... But in other cases this is literally a light that is so intense or dangerous for retina, that it causes immediate BVD.
        In such cases the best thing to do is not to train the binocular vision but avoid the dangerous light.

            Mrak0020 I feel excuriating muscle pain the very moment I look at screen and I can't focus anywhere far immediately after.

            Same, better or worse if you look with one eye?

                mike
                Same. I feel how muscles on both eyes work together though with one eye patched, so...

                • mike replied to this.

                    Mrak0020

                    Short or long test?

                    I did a short test many years ago and my conclusion was the same as yours. But with the long test it was much better.

                        mike
                        Long 'cause I'm trying to reduce the eye damage from light.
                        And damage from light is impressive: I see neon colors instead of normal colors, bright objects that are printed on retina are brighter and stay longer etc

                          a month later

                          martin sometimes a machine is used that flickers light at certain frequency in order to wake the weaker eye up and force it to be active.

                          I use such a machine, it's called the TransLid-Binocular Interactor (TBI). It's just a that flickers between each eye a few times a second (I have no idea how it costs $300 as it's a pretty simple device).

                              4 months later

                              ryans Curious on your results with using this device. The BVD theory seems to be the most accurate at this time since it is the only one that explains why patching works.

                                  ensete lpowers0918 So the purpose of the TBI is an anti-suppression device. People with BVDs often suppress one eye; that is, the brain does not actively fuse images between both eyes. The TBI is supposed to force both eyes to be used by creating a flicker.

                                  The device does seem to help with suppression but it hasn't helped my symptoms. If you're electronic inclined, I am pretty sure you could build one for like 30 bucks. It is literally just two LED lights that flicker between the left and right eye.

                                      8 months later

                                      Highly interesting theory.

                                      It seems to be that I have eye strain from temporal dithering. I'm pretty sure that I have eye strain not from PWM because I have Radex Lupin devices and I found several devices that have PWM but do not make eye strain to me, and vice-versa I have devices without PWM but with eye strain.

                                      I tried to use Lenovo Thinkpad T14s, which causes me eye strain, with the patch on one eye, and magic - I can use it with almost no strain.

                                      I have scoliosis so it seems to be that my head has a small tilt which seems to be causing BVD.

                                        Zodios The cause of my binocular vision dysfunction seems to be that one eye is physically higher than the other, causing vertical heterophoria. It's not very noticeable but I thought it might be related and a BVD specialist picked up on it immediately. So minor variances can indeed cause BVD.

                                          2 years later

                                          bkdo

                                          When I do this test, the object moves to either side depending on which eye is closed.

                                            Just wanted to drop one anecdotal note here. I have different prescription strength for my contact lenses. While seeing if I could reduce the difference between the eyes again I noticed that with one combo it felt like a short blackness upon moving my vision over larger distances. This was rather prominent. As far as I could tell this wasn't blinking and I researched a bit on out suppression at that time. Felt like some switch was happening.

                                            I've had tons of eye checks and adjustments. My measured strength is -2 and -2.75. That gives issues pretty fast, and I've used -2.25 and -3 for half a year or so. After extensive experimentation I ended up using -2,5 and -2.75 that for some bizarre reason works really well with my Retina screens. What seemed like suppression happened with -2.5 and -3.

                                            I know in some cases it can be helpful to reduce the strength of one eye to prevent switching back and forth on what eye takes lead. Might be worthwhile for others here to do some actual experimentation with prescription adjustments for a few hours each, instead of blindly assuming that the adviced strength is what works best.

                                            dev