Hello, I wanted to summarize what helped me so far and what might solve the problem, or some parts of it for good.

I have been diagnosed by an optometrist (not mistaken for an ophtalmologist/eye doctor) to have eye convergence excess and resulting accomodation insufficiency. That means my eyes do not work together properly to hold a single image instead of seeing double and I am already putting a lot of effort into that in real life.
Together with this my visual system (not eyes, but brain) is very sensitive. This might be the cause of the problem I have with modern displays - in some yet uncomfirmed way they might disrupt vision, causing my system to work very hard to keep a clear and singular image/text. That leads to eyestrain, overload, headache and migraine.

The help for me first were glasses with prismatic lenses, that ease of the problems by about 50%. I can see with them clearly only up to one meter and I was recently using an iphone 6plus that was before unusable for 2 or more hours with a slight discomfort and very small to zero headache after.

Another help is doing a visual therapy, that should make me able to use my binocular vision like a healthy person. That consists of about 6 months of 30mins daily exercises using - brock string, switching various lenses while reading to learn to adjust accomodaton, and tranaglyphs with 3d glasses, that I have to keep connected in one image while they move further and futher apart.

I hope that this solves the problem. Regarding flicker sensitivity I do not know if that helps, as noone knows which individual devices really do flicker and which not and how much. Its up to everyone to test with their own measuring tools. There is a possibility that flicker is disrupting the vision and when you get it fixed, it doesnt bother you anymore.

You can probably do a little test of your own with the brock string - either find one or make one. Then when focusing on the middle bead (2nd), try to be aware of seeing double the closer(1st) and the farther(3rd) bead and the string too. Then, the string should meet in the bead youre focusing onto. If it crosses sooner, you have convergence excess, if it crosses behind it, you have the opposite.

    martin Before modern displays, did you have any symptoms (like reading printed books)?

      I can attest to martin's solution because I am similar. In 2012 I was diagnosed by my optometrist as having a convergence insufficiency as well as accommodative insufficiency after a binocular vision exam. I did some pretty dedicated in-office vision therapy for about a year, and weekly "maintenance exercises" which I do on the weekend to try to hold what I have. I'm still symptomatic, but not nearly as much as I was during the initial symptom onset.

      I haven't had a decent chance of testing pure print for a while, but on Saturday, July 21st I did. I was reading a whole bunch of mail with fresh eyes that day when my eyes started to ache and I got that familiar "junky head" feeling and had to take a break. Since I do most of my reading on some sort of screen (either computer monitor or phone), I haven't had an extended period of reading the printed word in a while. So it would appear my symptoms are caused from reading overuse, and perhaps the fact that my brain works harder to maintain fused vision than another person acting as a control.

      Separate from this issue is severe head pain and back-of-the-eye ache when viewing a computer monitor which has an LED backlight. Instead of taking hours to set in, it takes minutes or even seconds... I can literally feel it immediately. My only "solution" so far is total and complete avoidance of these displays, but research is ongoing to try to find a way to tolerate them (as I cannot hide forever!)

      ryans no, not that I remember. But recently I was reading material on a very glossy page and after that I had similar pain and discomfort, however never as big as with the displays. Once I heal my eyes and I know theyre not the problem anymore, I can figure out what else might be (maybe obvious PWM flicker will still be an issue after).

      Have you tried eyepatches?

      They're probably not good for day-to-day use, but good for certain emergencies, and they might help test whether conversgence issues and double vision are the sole cause of your eye-strain. (I am strobe-sensitive and sometimes use them for extra protection against turn signals and other flashing lights. I don't get any extra protection from ordinary eye-strai though.)

        6 days later

        Ananiujitha I have, thats how I got started with my optometrist. Seemed to improve a lot, but Id like to keep my binocular vision. Also that one is hard to fool as even when your eye is in complete dark, it tends to converge to where youre looking with your uncovered eye. You can try it yourself. It does not get deactivated by covering it. No image fusion is needed of course, but the problem might not disappear completely. Also some issues like accomodation still apply to only one eye being used. Eyes and vision are separate things, one being the organ and the other the processing in the brain.

        20 days later
        a month later

        I wanted to share my progress with the eye therapy here so far. Recently I have been asked by my optometrist to participate at their conference as a model for the problems theyre trying to diagnose and solve. Few other optometrists that were being taught how to measure these issues properly tried to diagnose me, it was all recorded and later used as education material.
        I must say I have a new level of admiration for the guy who diagnosed me originally, as he does his work way above what other specialists there were capable of. Some joked after that "in a regular office this would take 5 minutes, youre testing him for one hour", implying how "well" other optometrists do their jobs.

        Ive told him my concerns that the therapy might not work, or that the glasses dont work all the time and I still get headaches with them sometimes.
        He said the glasses fix about 1/4 of the whole problem, and that after 2 months of the therapy it is way too soon to see results - I have improved a lot, but he said the most important thing is to integrate what I have been training into daily use. Then the last part of the therapy will actually be training to be able to use my eyes in the opposite extreme of what they are doing now (excessive convergence, resulting accomodation issues, getting stuck in a loop - adjusting one calls for adjustment of other, conditions on the screen change, its called again until the pain we all know so well - this makes a lot of sense to me in regards to flicker, but lets not get too ahead).
        He also mentioned that it is very common to feel like you can tolerate problematic displays right after the training for an hour or so, and for that to fade, as lasting change needs a very long and slowly progressing approach. Also good days and bad days are very common (sometimes the pain doesnt set in so soon, other days its instant).
        He also mentioned he doesnt know if it will cure it 100%, as there is still a lot of unknowns in this field. He siad they tried to publish some articles but a lot of the medical community doesnt care or think its bullshit, and consider the people to be a psychological case.
        So a lot of what you described here in regards to this condition actually makes sense "by the book". Lets see in 4 months then how much this training will really help.

        But if you get better right after eye exercises, theres a big chance this is part of your problem and you just need to find the right person to actually help.

        Just a story to put all this into another perspective - there was a lady in one of the optrometrists office with such bad migraines, that some doctors drilled a hole in her head in attempt to stop them. It helped, but since then she sees double. He crafted glasses to fix that and shes eternally grateful now, as the diplopia is way less of a problem than the migraines according to her, even though shes dependent on the glasses now.

        Very happy to read about more people recently finding a solution.
        I had some poor convergence 15 years ago. I corrected it by doing exercises. I have not "trained" for a while, and I know that doing that and the Tibetan wheel helps provide some relief. However, I am very reluctant to believe that convergence is my issue. And I hate "believing". I would like some of the doctors I have paid hundreds of dollars to tell me what is what, instead of walking in the dark.
        My convergence cannot improve or worsen from one day to the next following a bloody phone update. I was at an osteopath this evening. I had not used the phone for a day and was feeling well already before going in, even after 10 hours on my Mac which I could not believe until months ago I would be able to tolerate.
        Then after the treatment I turned my phone on and vaguely looked at Google Maps. All my health gone within seconds. And I am not imagining things.
        I am really clueless, as I could use this phone in the past without any problem. It is worse than the worst allergic reaction I can think of. It is one of those days I would really like to throw the phone out of the car window...it has become a nightmare.

        That said, crying is useless. I need to react. Since I do not currently have any other plan, I will go back to exercise my eyes' convergence...and try to implement any good habit I can think of, like sleeping more or eating well. But, boy, I see it really dark...

          AGI The light or flicker might be doing something to disturb visual systems ability to do proper eye teaming, so its not that your vergence all of a sudden goes bad. Its always bad, you compensate, in some conditions you cannot.
          Also dont just do the exercises, it has to be a guided program in varying intensity and progressions.

          a month later

          I wanted to share my progress here. I was doing the exercises half-wrong for 2 months, so I was strenghtening the already overpowered eye muscles (thats a reminder that doing something at home that you found on the internet might either make it worse, or might not help at all if it doesnt apply to your specific case).
          Now I am on the right track. After two weeks my camera display stopped causing me nausea and stinging pain, isntead it is fine and over time it develops into a pressure. I shouldnt see any progress below 2 months, but I think I am already seeing it a little bit now. Also when testing a painful iphone, I was able to relax while looking into it, as I know now which muscles get tight and cramped and I know how to relax them. I cannot do it for too long yet, however the change is quite noticeable. I my case a complete removal of symptoms via visual therapy is at 84% of cases, so I will see how it develops.

          Also when I am tired, I cannot successfully complete the exercises that I did with ease the previous day, maybe explaning why some people have better or worse days with certain displays. I also guess that people who had intial pain from new displays but got "used to it", might have had similar problem but with way less deviancy (mine being extreme at approximately 15 out of 12 measuring points), so therefore the staring into the displays served in itself as a form of therapy and the eyes adjusted.

            martin I've been to another eye doctor recently and have a follow-up appointment next week. She said my eyes move slightly inwards which can be corrected with prismatic* lenses. Reading your description it almost sounds like you have an opposite condition, where the eyes want to move outwards? When I put on the testing glasses and looked through them I quickly got the same kind of eye strain that I have while using certain software (Firefox, some games, etc...). Covering one eye seemed to remove the effect.

            * not sure if this was the right term, I should ask next week

              KM Good! Hope you get some quality care. No mine is the same. It is bit more complicated though, as not only vergence (how eyes move out or in) but accomodation (distance/near focus in each eye) play a role. Literature is badly needed and very little is written. Check here:
              https://i2.wp.com/informationdisplay.org/portals/informationdisplay/issues/2012/03/art9/GIFS/fig2.jpg

              Basically I converge my eyes at a different plane than I accomodate at, having trouble with both. Using one eye removes or significantly reduces the issue, problem is the two are bound together so problems with one can influence the other, hence even one eye usage may not be problem free until you fix it for binocular vision. But to be clear, I could use my camera display with one eye very well, two eyes were problem. Some other things are a bit difficult even with one eye.
              Your eyes can either meet behind the screen (divergence excess or convergence insufficiency) or in front of it (convergence excess or divergence insufficiency). When you try to meet accomodation with vergence, your eyes get stuck in an adjustment loop and never relax, or they just literally strain to get both in line.

              Also - yes the prismatic glasses hurt intensely the first day I used them after some time, then my eyes got used to them. They also bent the image I was seeing, now it all looks normal. They dont help with everything though, which is a mystery to me, but one that I will be more clear on when I finish the visual therapy. They also only help by 1/3 of the complete deviacy I have, as full correction would be unusable. Mine is very off the charts so visual therapy is the only way. I should actually have visible strabismus (lazy eye), and none of the specialists know how its possible that I look normal. Supposedly overpowered it by my will lol.

                ryans Since the glasses, I didnt get a migraine, just slighter headaches from either prolonged use (hours) of a previously unbearable iphone, or from macbooks after shorter time - there the problem might be the larger display. I will see when my therapy is successfully finished and I can complete all the exercises with ease. Then the problem should disappear, and if it doesnt, theres more to it. Im not progressing very fast though, its gonna take months. Im training accomodation and vergence separately and then I have to train them at the same time. But I see changes already and I cant even successfully finish difficulty of level 2 out of 5 or more. So theres hope.

                  martin I didn't have any eye strain issues for an entire month, then on Monday, I came back here to catch up on a month's worth of posts, and now I have eye strain again. You can't make this stuff up people! 🙂

                  Remember, I have two distinct eye comfort issues. The first one like martin's (convergence insufficiency and accommodative insufficiency), which takes longer to set in over time. We'll call that one issue #1. The second one is near instant and immediate sharp pain in the eyeballs if I look at an LED backlit computer monitor. We'll call that Issue #2.

                  With Issue #1, I notice more issues if I'm reading a lot of small text. Sometimes I will spend some time sorting a lot of Outlook e-mail, which involves reading it in the preview pane, filing it, etc. I will often have Issue #1 creep up doing this. However, if I'm looking at pretty charts and graphs and graphics, I find I'm usually OK, even with a full 40 hour work week. I also try to remember the 20/20/20 rule to give my eyeballs a rest by looking in the distance from time to time, or taking a break.

                  With Issue #2, forget about it. I avoid LED displays like kryptonite. Long live the Dell U2410 CCFL monitor I use both at work and home!

                    MagnuM I can relate to that. If I read small print the same thing happens. All LED screens kill me. That CCFL you use is it flicker free?

                      This gives some interesting results if you search on Google:

                      vision therapy site:discussions.apple.com
                      convergence site:discussions.apple.com

                      Looks like vision therapy is not a silver bullet.

                        ryans Im not sure how any of this disproves that it cannot work? Also convergence is one out of many issues with vergence. Just because you find one person online who said it helped partially doesnt mean it does not work. Actually quite the opposite - it points to the fact that its multifactorial and that the therapy indeed changed something. Its better to try for yourself. If that is your issue of course, and not something else. There might be no "silver bullet", everyones different.
                        Some people erased their symptoms completely by using eye drops and others by changing their medication for other issues. Unless you live in a country where examined for such cases costs like a new mortgage (USA), you cant loose giving it a shot.

                          dev