hpst My wager is still on Temporal Dithering. I think PCoIP analysis will prove conclusive to show the link between pixel movement and 'bad' devices. The only time I have felt symptoms on this computer is using a Shadow PC.
The good news is that there is a way to turn off Temporal Dithering, we just need access to it - so the fix has already been made.
So some thoughts on CBD/THC:
CBD oil is almost exclusively extracted from hemp, which is a subspecies of the cannabis sativa plant (saying that it's the male versus female variant of the plant is an oversimplification, although many people claim this). Hemp contains very little THC (varies from 0.03% in industrial hemp to a couple percent in medicinal hemp), and has many uses throughout the world. It is legal (the industrial variant) in all 50 states, although its close association with marijuana has led to barriers to its use (also the lumber and wood pulp industries have lobbied hard against it).
All variants of cannabis have a dozen or more "cannabinoids", which are a class of compounds including CBD and THC (the two with the highest concentration). THC is the only cannabinoid which causes psychoactive effects (the "high" associated with marijuana use), but others have varying benefits and effects on the central nervous system which are not well documented at present due to the stigma against marijuana impeding solid research.
What JLT and others have tried is actual "cannabis oil". This is oil that's extracted from the marijuana variant of the cannabis plant, and has varying amounts of THC. Some variants of cannabis oil, such as the now-infamous "Charlotte's Web", have been bred to have extremely low THC (<1%) and extremely high CBD (>50%). Others have a more balanced amount. It's common to see oils that are "90% THC, 7% CBD".
In my opinion, CBD is amazing for relaxation in combination with the other cannabinoids and natural terpenes found in both hemp and marijuana. Sadly, the CBD in actual marijuana seems FAR more effective, because THC boosts its efficacy. This creates problems - first of all, in many places THC is still illegal, and even if it is legal you can't exactly get high and drive to work so maintaining a consistent blood level of the drug in order to experience alleviation of symptoms becomes difficult.
The best effect, for those of you who want to try this and live in a legal jurisdiction, is to go to a dispensary and acquire a "high CBD strain" of marijuana oil. The biggest impediment to this is that in many places (my own locality, as an example) these strains are reserved for those with medical marijuana prescriptions.
The big question here is "does this work?", of course, and the answer isn't simple. JTL has had a cessation of symptomology (cheer!) but it is my firm belief that in order to see any benefit, one has to be diligent with application of the medicine, which can be difficult to balance with family, work, and other obligations since even at low doses marijuana tends to make one a bit "dopey" or "silly".
Gurm I've tried high quality CBD to no effect. I think weed or THC heavy vaped things help the same way any CNS depressant/intoxicant seems to help people. It just relaxes you enough to temper symptoms. Booze, benzos, opiates, anything that has strong effects is going to alter how you perceive things. Stay high and you can't be bothered.
hpst It may also be that, in cases where ezophoria is present, the CBD relaxes the muscles that are too tight, therefore adjusting vision. Big problem of mine was that I not only need to strengthen the lateral eye muscles after 30 or so years of misuse, but at the same time relax the inner (near nose and cavities) muscles to allow the lateral ones to work without having to do too much work. This is also the reason why sometimes having rhinitis can affect certain cases of heterophoria. In the opposite case of convergence insufficiency, what's needed is more effort at the inner eye muscles and not relaxation. However, bottom line, of course if you're very relaxed due to drugs or other inhibiting things, you might have an easier time with the problematic display tech.
martin I definitely think we need to get as many visitors on this site to provide more details of their eye condition(s). Maybe nobody here has 20/20 vision or perfect binocular vision. There has to be a link. That doesn't mean we all need to get our vision corrected, as that simply isn't physically possible in some cases. I am perplexed as to why 'normal' people are not affected by flicker/temporal dithering, maybe it is cumulative and the effects of use will be visible in a decade or two.
My STRONG suspicion is that this is a muscular condition. The fact that my eyes feel "tight" or "tense" when I'm having issues leads me to believe that something (LED, flicker, spectrum, intensity, etc.) is "triggering" my brain to tense the muscles around my eyes leading to a rapid onset of symptomology. Lately, between the new car and remodeling the basement I've spent a lot of time under questionable lighting - perusing the lighting aisle in Lowe's, installing new fixtures (and the flicker associated with them) in my basement, in and out of work, etc. and my eyes are just TIRED all the time. this leads to more rubbing, more straining, less blinking, etc.
If it's possible to simply force the eyes and muscles to relax through judicious use of ANY relaxant (whether it's THC, alcohol, or really anything), I'll take that option. I honestly don't think that there are EVIL DAMAGING RAYS (although the effect of blue light on the retina is definitely not positive) that are hurting us. This is a brain/eye/muscle/focus problem. There IS a solution out there, we just have to find it.
Gurm I am an identical twin and my brother has no eye issues, stereovision and 20/20, I got the raw end of the deal with my eyesight 
.
I have asked him recently how he is in work, at home etc. Granted at work he's still using older HP monitors, but still LED and no doubt from a value range. Also he uses an Xbox one, and iPhone pretty much all day and he never gets headaches or eye strain. Maybe he's been lucky enough not to encounter a bad device, but I doubt it if he's using the latest iPhone/iPad for hours at a time. I would say it also rules out any genetic pre-disposition as well. I might force him to use one of my bad devices soon and see how he gets on.
The only remaining issue as you mentioned is brain/eye/muscle problem, exacerbated by the dithering/xyz on devices.
diop I suspect that MOST of us, over the course of our lives, have overworked our eyes. I know I have. I've been on a screen pretty much 8 hours a day for more than 25 years. In my early 20's I spent more than a year developing video games, during which time I was coding 18+ hours a day with very little sleep. I'm sure we all have eye problems of one kind or another. Many of us have allergy/sinus problems. Many of us have TMJ. I don't think there's a strong commonality, but it wouldn't surprise me at all if it were a brain/eye/muscle communication problem exacerbated by inflammation, which seems to be the source of all of my woes in other areas, for sure. It would be great if a common culprit were found.
There are simple diagnostic techniques that you can try at home. I encourage people to write me message here or an email and Ill help. They're simple and won't replace a laboratory testing, but they still give good results. Ive already exchanged emails with a few people and all seemed to have some sort of vergence/accomodation problem.
Why the display tech causes this issue to manifest I dont know, but I believe there is another way of finding out. If tech solution is so evasive, maybe understanding the underlying health issue could help us understand what the tech is actually doing wrong. Write me and Ill try to help as much as I can. One user from here that Ive met in Prague wrote me yesterday that the advice I gave him helped and he can now use some devices more than before. That is amazing as he didnt even do any training, just alternated one and the other eye and tried adjusting one after the other, before using both. This issue is new, and treatment experimental, and Id be excited to hear more news like this.
Found this interesting and inspiring video
AGI What she says is very much very close to Feldenkrais / Alexander concepts. Actually i have improved in many respects my chronic back pain just by changing my movement habits.
I have also improved my tolerance to many bad displays with eye exercises i.e. by improving eye flexibility and enhancing the eyes ability to move freely in many directions.
However i do believe that there is some kind of toxicity in the LED lights technology.
See this other
Curing learning-related vision problems | Dr. Vicky Vandervort
What she illustrates ~ 5 min 40 sec into her video looks like what happens to me when I read on certain displays.
Has anyone exercised with a Marsden ball, perhaps @martin?
It looks like it can be used in different ways, e.g.,
NeuroPerformance Prac - Marsden Ball
Bunt Ball: Optometric Vision Therapy
assuming Bunt Ball is a synonym.
This looks very cool
@martin Could you please recommend on the length of the Brock string? Thanks!
Many of us, including myself, often found correlation between onset / worsening of vision issues and flu, cold, and sinusitis.
This doctor says that flu and viruses can indeed affect binocular vision and induce eye turn / strabismus.
I do not want to sound like I am sponsoring someone, but also this other video from the same doctor is interesting. She successfully cured a kid wearing Coke-bottle glasses, enormously reducing her lens prescription.
Patient Update: Success With Decreasing Lens Prescription In A Five Year Old
That is what I saw happening at a workshop by Leo Angart. Some attendees, all adults over 50 yo, went to a nearby pharmacy and bought glasses with reduced prescription twice within the two days of the training, consisting of exercises with Brock string and else.
Looking Inward: Treating Convergence Insufficiency (CI) with Vision Therapy | Wow Vision Therapy
I use Cymbiotika Nexus which has CBD. But I’m sure there are many good brands. I’m in the US. I only take 1 pump vs the 14 pumps recommended. But taking 2 pumps definitely relaxed my eyes so that the MacBook was tolerable. CBD is quite amazing.
