Serotonin is inhibitory neurotransmitter that activate parasympathetic system which make pupils constricted and more sensitive to lite.flickering.
Thus @Seagull approach to serotonins make sense.
The other point is oculomotor nerve compression due to pressure - https://ledstrain.org/d/3143-found-the-root-cause-of-my-led-eye-strain-and-an-effective-treatment-plan
GABA is also made in the gut and have the same sort similar effect like serotonin.
For example, Epilepsy is connected to GABA deficiency - https://www.sciencedirect.com/science/article/pii/S1059131122001601
So @Seagull , maybe your diet fixed your GABA?
Ok, got my bloodwork results back and they're confusing (Of course they are!!)
My Ferritin is in range but in the lower part of the range but my serum iron is at the HIGH end of the range... odd. My Ferritin is around 50, but like @balthazar said in the original post it may need to be >100.
So that said I asked my GP if there's a way to safely increase my ferritin levels without pushing my serum iron too high... we'll see what he says. I'm not a fan of this doctor so I won't hold my breath on a solution.
I did think about something interesting though... I have a lot of autoimmune issues and I've was taking turmeric supplements for 4-5 years. I stopped a month ago because I read something about it being bad for the liver. The interesting thing is that apparently turmeric decreases iron absorption. Combine that with the fact that I don't eat red meat and I probably did a number on my Ferritin stores. Perhaps it was even lower before I quit and it's working it's way back up? Just a guess.
Also interestingly @Seagull commented here that turmeric/curcumin makes screens worse for them as well. Maybe that's connected? Maybe I'm just crazy? Maybe both! 
Hi there. Sorry to leave you hanging, @Seagull
You are still in Batch-1 to receive your Daylight Computer, alongside our earliest shipments.
Our manufacturer in Taiwan had to replace a key machine part, and it has delayed our fulfillment considerably. So the Batch-1 timeline has unfortunately been moved to October.
Please feel free to reach out to us if you have any questions at all - [hello@daylightcomputer.com](mailto:hello@daylightcomputer.com)
We invented a tablet to serve the eye-strain community.
We’re Not E-ink
Our LivePaper technology looks like e-ink, but allows you to browse the web, watch videos, and even play games - all with no blue light, no lag, and no flicker.
Free Tablet Giveaway
We’re giving away one free tablet! Leave a comment and you’ll be entered in the raffle to win.
Leave a question, feedback, your personal eye strain story - even skepticism : ) We know this is a new product, so we expect people to be a little skeptical! We can’t wait to see your comments.
We’re from a company called Daylight Computer Co, and even though we’re doing our official launch soon, we wanted to offer this sneak peek to the community that we think will most benefit from our technology.
The support of the eye strain community means a lot to us, and we hope you’ll stay with us up to our launch, and beyond!
Give-away winner will be selected and announced on 6/15.
Check us out here, and subscribe to stay updated!
GIVEAWAY ANNOUNCEMENT:
Dear LEDstrain community,
Thank you so much for sharing your interest and comments here. We really appreciate it. Apologies for the delay - our small team was a bit overwhelmed by the response to our launch!
We are so excited to announce the winner of the Daylight Computer giveaway. Our randomly selected winner is......drumroll drumroll drumroll.....Seagull!
Congratulations @Seagull! You will be one of the very first people to get your hands on the Daylight Computer! Six years of research, design, and work went into making this product, and we truly hope you love what we created!
Please email us at: hello@daylightcomputer.com for the logistics of receiving the Daylight Computer.
Thank you everyone for your interest and support. Although only one user is selected to receive the Daylight Computer, all of the stories you shared meant so much to us. We hope to succeed in our first product roll-out and bring many more eye-friendly devices to the world!
If you have any questions about our product or how it is more eye-strain friendly - please continue to comment or contact us directly!
Sincerely,
The Daylight team
https://ledstrain.org/d/1111-external-graphics-egfxegpu/8
From @Seagull
When turning dithering off you'll only see the difference on a laptop screen. Desktop monitors do their own dithering in addition to any graphics card dithering. Laptop screens are dumb, and rely on the graphics card to dither for them.
Emphasis mine.
But then this is Apple...
photon78s I just tested a Mac Mini M2 using my 240fps cam/microscope setup and I can confirm I see flickering even when Stillcolor is enabled.
This could be PWM or LCD Inversion or something that's not temporal dithering. See @Seagull very insightful post here.
jordan So my friend tried still color on his MacBook air m1 2020. He has a Boox Mira eink monitor connected to it and you can see how it flickers but then when stillcolor is enabled (dithering off) the flickering stops.. BUT when he moves the cursor the rest of the screen still flickers? Is that some sort of SW flickering or is that the nature of Eink. Check the video below (there's sound too of him explaining it) https://imgur.com/a/r9kT9uq
Awesome stuff. The mouse cursor effect is also discussed in this old thread about using a Paperlike screen to detect dithering.
tl;dr disable temporal dithering on your M1/M2/M3 with Stillcolor.
I got 16” M3 Max MBP about a month ago and it’s been absolute hell. By far the worst screen I’ve ever used. It’s like staring into lasers. 1600 nits! Previously I’ve used a mid-2012 retina MBP for almost a decade, and briefly a 2019 16” Intel MBP (at reduced brightness). Those gave me no eyestrain, no dry eyes, no light sensitivity, no inability to focus.
So within the first 24 hours of getting the M3 Max I found LEDStrain and learned about PWM and temporal dithering, and so did my adventure begin of trying to make my new laptop usable for more than 1 hour a day.
At first I thought I could just connect it to an external monitor and adjust the color profile and brightness and everything will be fine. By the time I realized how futile those hacks were my 2-week return window was through.
I tried everything mentioned on this forum, including @NewDwarf boot-args, BetterDisplay with mirrored virtual displays, Iris, SwitchResX, etc. Disabled motion, transparency and True Tone, switched to sRGB, dimmed blue light, turned on Dark Mode, turned off Dark Mode. These measures helped a tiny bit, but my eyes still became severely fatigued after 1 hour of use (even on external monitors).
I wanted to see how PWM and temporal dithering look like. I needed quantify these things to determine if 1) they were the cause 2) if any other display adjustments I make have an effect.
Used my phone camera in manual video mode with a really fast shutter speed (1/12000). Detected PWM on
PWM-free:
Interestingly, some of these PWM-free displays which I’ve used for years were suddenly giving me severe eyestrain when connected to the M3 Max.
To visualize temporal dithering you can run a true video capture of your screen though ffmpeg, which can create a diff of each successive frame pair and output a new video of those diff frames.
sudo port install ffmpeg
input.mov in Terminal with this command:ffmpeg -i input.mov -sws_flags full_chroma_int+bitexact+accurate_rnd -vf "format=gbrp,tblend=all_mode=grainextract,eq=contrast=-60" -c:v v210 -pix_fmt yuv422p10le diff.mov
This uses a filter called time blend (watch this crazy demo) which layers every frame on the frame preceding it using grainextract blend mode (previously called difference128). It gets the absolute difference of each RGB value in a pixel then adds 128. So if there’s no change from frame to frame, the output pixel should be RGB(128 128 128). We then adjust the contrast to make the difference more visible, and finally output a lossless video. I’m not an ffmpeg expert but the above command does the job. To output a compressed mp4 use -c:v libx264 diff.mp4. This does the job of demonstrating dithering at much lower file size. Not pixel perfect but passable.
This doesn’t work. I analyzed a lot of screen recordings from the 2012 MBP and the M3 Max and came to the conclusion that the recordings are at least a step before the application of temporal dithering. Whatever looks like dithering here is likely an artifact of compression.
Encouraged by @Seagull capture card thread, I got a Blackmagicdesign UltraStudio Recorder 3G. It accepts HDMI input and connects to your Mac using Thunderbolt 3. It can capture QuickTime Uncompressed 10-bit RGB at 1080p60. This is more than enough for our needs. But you gotta be careful with uncompressed videos, 3-4 seconds clock in at ~2GB.
Here are the results from the devices I had access to:
Dithering ON, M3 Max, Sonoma desktop, 1s capture @ 1080p60
Just viewing the time blend video is pure torture! Makes you acutely aware of the muscles behind your eyes. If anyone wants the uncompressed recordings I can upload those but they’re heavy and look similar the compressed ones.
Time blend videos with dithering disabled simply show a plain gray screen.
Some findings about dithering:
Now that I knew that my laptop applies temporal dithering, I knew it was the cause for my eyestrain. Because the eyestrain was there even while using PWM-free displays, and it’s the only perceivable difference in output from my 2012 MBP and my M3 Max.
I read all over this forum that it was impossible to disable dithering because the new Apple silicon GPUs are only capable of handling 10-bit color, and are always dithering no matter what. Seemed unbelievable and I was determined to find a solution with code.
I read this progress report on the Asahi Linux blog by marcan (they’re doing some incredibly hard and important work over there) about reverse engineering the M1 DCP (Display Coprocessor). They proved the CPU and DCP communicate back and forth. Messages like
IOMobileFramebufferAP::setDisplayRefreshProperties() at the DCP interface were encouraging and hinted at an ability to configure the display.
And over at their DCP tracer a IOMobileFramebufferAP::enable_disable_dithering(unsigned int) message was traced. All evidence that are there mechanisms in place to control dithering. The question now became how to send those messages.
In my rabbit hole dive I also came across 2 important tools:
ioreg which shows your I/O RegistrySo in the logs I saw a property called enableDither = Yes under a service called IOMobileFramebufferShim. All of this now seemed inter-related, and the puzzle pieces were falling into place.
Based on all of that I figured a good starting point would be IOMobileFramebuffer which iPhone Development Wiki describes as a “a kernel extension for managing the screen framebuffer. It is controlled by the user-land framework IOMobileFramework.” On macOS it’s called IOMobileFramebuffer. It’s a private framework with not much literature on it. One way to examine it is to run it through a disassembler.
So I loaded /System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_arm64e into Hopper, selected IOMobileFramebuffer and started looking at the symbols and found 2 interesting routines:
_IOMobileFramebufferEnableDisableDithering_kern_EnableDisableDitheringMy best guess was that _IOMobileFramebufferEnableDisableDithering is a wrapper around _kern_EnableDisableDithering which does the real work. Or is it the other way around?
_kern_EnableDisableDithering is a very simple function, the crux of it is this:
IOConnectCallScalarMethod(r0, 0x1e, &var_10, 0x1, 0x0, 0x0)
Calls selector 30 on the IOMobileFramebufferShim object with a boolean value. So I quickly made a command line project in Xcode that does just that and this is what I got:
(iokit/common) unsupported function
Uh oh! Disappointing. But I was not about to give up-- IOKit can return kIOReturnUnsupported for a variety of reasons, one of course being a complete lack of implementation, another being invalid or out of bounds arguments, or possibly a lack of privilege.
So I then loaded the IOMobileFramebuffer framework dynamically with the help of this gist and invoked IOMobileFramebufferEnableDisableDithering directly and as expected got the same result.
Maybe calling it wasn’t allowed from user space? But I wanted to dig deeper before messing around in kernel space.
So then I stumbled upon IOConnectSetCFProperty and I remembered enableDither = Yes from the registry. I thought I’ll just set it directly on the IOMFB object and maybe it will interpret it and affect the display downstream. So I did that and got:
(iokit/common) unsupported function
Again. I was starting to lose hope at this point but in a last ditch attempt I thought I will just modify the I/O Registry directly, even though my understanding was that the registry was a lens into device state and modifying it from the top won’t affect the devices per se.
So I did just that.
kern_return_t ret = IORegistryEntrySetCFProperty(service, CFSTR("enableDither"), kCFBooleanFalse);
And got:
(os/kern) successful
Awesome! I ran ioreg -lw0 | grep -i enableDither to see if the registry was touched.
| | | | "enableDither" = No
| | | | "enableDither" = No
| | | | "enableDither" = No
| | | | "enableDither" = No
| | | | "enableDither" = NoI thought I was dreaming! I wanted to verify so I plugged my capture card, recorded 3 seconds and ran it through ffmpeg and I couldn’t believe it! Dithering was gone! It was that simple.
The below video is a capture of YouTube playing a 1080p60 video.
At first dithering is enabled, then at 00:03:59 dithering is disabled and watch for yourself.
Dithering ON then OFF, M3 Max, Sonoma, YouTube @ 60fps, 1080p60
It turns out modifying the I/O Registry is a common way to tweak driver and device settings and there’s even a command line tool for that. However, the device driver/kernel class must allow and implement the inherited IOService::setProperties method for it to work.
Over the next couple of days I verified it with a few more recordings, including ones where I disable dithering mid-recording and the effect was immediate. Best of all I didn’t need all this proof-- I could simply use my computer again and suffer minimal eyestrain.
The downside of this method is that enableDither is reset back to Yes on computer restart. There’s possibly a way to avoid this by modifying the driver’s plist which might contain those properties, but that’s an exercise for another time. A simpler solution is Stillcolor which I developed to disable dithering on login and whenever a new display is connected.
Stillcolor is a lightweight menu bar app which simply disables dithering on login and whenever a new device connects. It’s pretty much in beta at the moment and needs M1/M2/M3 and macOS >= 13 to run. Tested on macOS 14 only, so will appreciate feedback from everyone here.
Please bear in mind that there could be unintended consequences from disabling dithering, so use the app at your own risk. The app is released under the MIT license.
(For some reason Chrome gives a suspicious download blocked warning-- I don’t know know why it does that, you can safely ignore it)
Make sure to enable “Launch at login”
To check wether it did the job, run the following in Terminal:
ioreg -lw0 | grep -i enableDither
Should see 1 or more ”enableDither” = No.
To re-enable dithering simply uncheck “Disable Dithering.”
A visual test that works for me is the Lagom LCD Gradient (banding) test
Set your built-in display’s color profile to sRGB at full brightness and look carefully at the gray parts, you should be able to see subtle banding when you disable dithering which happens in realtime.
Disabling dithering alongside other measures such reducing brightness and blue light will make using Macs enjoyable again. I think the built-in displays are still awful, and I recommend using an external monitor which you’ve previously been comfortable with.
Special thanks to my brother Ibraheem for letting me test on his Mac and display!
Hey folks,
Decided to make a new thread just for that question.
As I mentioned in another thread, I have a problematic laptop that uses Intel Iris Xe Graphics video card that dithers and gives me massive eye strain and headache on any screen (internal or external). Can't install ditherig because it's a work machine.
The user @karthi3219 proposed to me to use a video capture card to capture the HDMI output of my laptop and to display the video on another PC/laptop that has a 'good' video card. I bought a gaming video capture card (AVerMedia LIVE Gamer ULTRA) to test that but it was with terrible quality and high latency. And I am using 1080p with 60 hz monitor. Now, I am thinking of building a PC and buying a more expensive PCIe capture card (from Magewell or Blackmagic). But before I burn more money trying to find a workaround to this issue, I want to confirm with you guys whether it's a good idea or not.
Questions:
Would such a setup work? Because in theory I am starting to think it shouldn't work - the video card capture device will capture the dithering, too. And the video will have the dithering effect. The difference would be one is HDMI signal, other is a video. So, maybe there would be a difference of how my eyes react to the video.
Is it possible that dithering could downgrade the quality of the video? I suspect this might be the reason why I get such a bad video quality with my current video capture card.
I will be very happy if @karthi3219 could chime in on the thread, too. Maybe he could give insight about his setup and how is the quality, latency and how about the dithering that is also being recorded. I am also tagging @Seagull since he has done some testing with video capture cards and has knowledge.
Thank you for your time.
@Seagull Ok, thanks. So it has 60Hz PWM. I'm currently able to tolerate many hours a day my Honor Magic 5 pro with 120 Hz PWM.
My theory is actually that the lower the better. When it's the normal 240Hz to 2500 Hz my eye get bloodshot very quickly.
I was almost getting the Lenovo ThinkPad Plus g4 with the e-ink screen with OLED, thinking also that the 60Hz would be better and then I'd have the e-ink to fall back into if my eyes get really sore. But then it seems now that Lenovo has whitdrawn it.
@Seagull do you have further thoughts on this?
I'm really intrigued by this concept. For some reason, I can use most laptops (as long as they don't have PWM) but external monitors almost always cause me problems (even when they don't have PWM). I am currently using a monitor from approximately 2011.
Here's a waveform from LaptopMedia from a laptop that I can use all day long without issues. It has a very slow 31.9 ms response time.
I may play around with my oscilloscope next week.
Seagull I think I've probably adapted to dithering patterns produced by different combinations of monitor/card. Hence, any changes produce discomfort as I'm no longer seeing the same pattern. I will test this out at some point by seeing if I can adjust to an uncomfortable card. I know I can adjust to uncomfortable smartphones, so I am fairly confident this is the case.
Hope it's ok to bump this old thread but I'm beginning to suspect this could be the issue for some of us. Do you still think this theory is true @Seagull ?
I have different scenarios and want to know if dithering is taking place:
(1) GPU Dithering: YES | MONITOR: 8-bit : (Y/N)
(2) GPU Dithering: NO | MONITOR: 8-bit : (Y/N)
(3) GPU Dithering: NO | MONITOR: 8-bit + FRC : (Y/N)
In other words, I bought a new LG monitor that has 8-bit+FRC. If a PC/Laptop GPU's dithering is disabled, will the monitor still force the GPU for dithering or it will only display 8-bit colors?
If I buy a monitor that is 8-bit only (NO FRC) and my PC/Laptop GPU's dithering is enabled, will the 8-bit monitor be forced to display 10-bit color by dithering or it will only display 8-bit color with no dithering.
@Seagull I tagged you in this post because you might have an answer for me
@Seagull writes about potential passthrough here: https://ledstrain.org/d/703-i-have-bought-a-capture-card/11
This is a great video of your iPhone SE 2020. Many thanks and congrats for capturing this.
It may be worth sharing on other forums like this MacRumors thread.
Note -- I needed to change the YouTube video to "720p60" to see the flicker (dither). The default of 420p (which I guess is based upon my bandwidth) showed no flickering at all.
Are we sure this is dithering? Could it just be LED inversion or LED light flicker (the same as an LED bulb would flicker, unless flicker-free)? Curious about @Seagull hypothesis on what we are seeing?
Any chance you can test it using ditherig?
Just looking at it makes me sick.
It looks like the microscope is only about $20 USD, that sounds a great price to investigate this, is that about what you paid?
Stumbled upon @Seagull 's old post ( https://ledstrain.org/d/946-neurological-malfunction/4 )
wherein he mentions that curcumin, silicon dioxide, and cooking oils make his symptoms worse.
This is interesting because my problems with brain fog that gets extra bad from screens, but can persist to a lesser extent even without screens started around the time when I had been taking COPIOUS amount of turmeric (curcumin is its active ingredient) for an an extended period of time. Salt does seem to make me mildly worse also, but I never thought about it being a silicon dioxide issue, and not salt in and of itself…interesting.
I haven't had any turmeric for years now, but symptoms persist.
One of my current theories is that it's entirely possible that something or other that turmeric is plentiful in - some fucking metal, or substance or whatever is stored up in my body and is wreaking havoc, and causing issues.
Kinda like when people with an MTFHR gene mutation can't process folic acid properly, and food enriched with folic acid can seriously mess them up, but the majority of people have no problem with processing that particular nutrient.
The question is: what is it about turmeric/my body that's causing this mess?
One of the things is salicylates. I do respond very poorly to them, but I still have brain fog even on a low salicylate, no turmeric diet. So it's gotta be something else.
@Seagull , any thoughts on this matter? Any common nutrients, vitamins, whatever that are found in turmeric AND other foods that exacerbate your symptoms?
You haven't, by chance, done any genetic testing and found you have some funky mutations? (I'm thinking about doing that myself in the near future)
SO FAR, I've found zinc to be helpful for reducing brain fog/computer dizziness. Cars with bright led lights change from painful to look at to mildly annoying.
AND, very interestingly: Parboiled rice (it has all kinds of b vitamins) - lots of brain fog. White jasmine rice (not a whole lot of vitamins) - much much less. White rice noodles (highly processed) - the least amount of fog.
IN regard to cooking oils, I react poorly to cooking oils too, but basically the high salicylate ones (i.e. all of them except for sunflower, rice bran, and a couple of others I don't remember) IN MY CASE - sunflower oil seems fine no brain fog noticed …so if @Seagull you react poorly to sunflower oil, it's likely not a salicylate issue in that particular case.
People with dietary issues, let's compare notes.
P.S. I just put "salciylates" AND "Silicon Dioxide" intolerance into google a rando website popped up where someone supposedly stopped being intolerant to both after taking vitamin K.
NO IDEA if this is legit…but I may well experiment on myself
News from me, on this topic:
I see now that my camera is not great for my purposes. Posting the 2 result vids anyway (so it doesn't all go to waste ):
Acer Aspire 5750G laptop (inbuilt display).
Lenovo IdeaPad 320 laptop (with Dell 2408WFP external monitor)
bkdo At the parts where the paper is in contact with the screen (like it should), visibility is very good. At the parts where there's a 2-3mm distance between the paper and the screen, visibility is very blurry (text is unreadable). So I'll probably try one of the options suggested by @Seagull.
Looking forward to hearing your results.
Edit: For good visibility, there shouldn't be much light falling on the paper itself. My only lighting is a lamp that sits behind the screen, illuminating the wall behind it.
Hi @Seagull,
Thanks for answering. I’m happy to share; here’s a history of events. Sorry if it’s too verbose
2018 February:
· Developed tardive cervical dystonia. I’ll come to this back in a bit.
2019 Autumn:
· downdosed a bunch of meds abruptly (aripiprazole, paroxetine, biperiden, baclofen, pregabalin); I didn't stop them cold turkey, but reduced the doses by like 90% down. This destabilized my CNS making me extra sensitive to all further dose changes
· Began seeing big rainbow halos around light sources (which I currently don’t) and got diagnosed with “spasm of accommodation”, a diagnosis that was repeated 2 years later by another doctor.
· Developed severe myalgia and muscle spasticity that got permanently worse when I did any sort of significant exercise. This included especially my inner thigh muscles, as they were the ones I was exercising at the time. Everytime I wasn’t careful and made my muscles worse with exercise, the only thing that helped was raising my magnesium dose even higher. I attribute these muscle problems to the downdosing of aripiprazole, baclofen and pregabalin.
· Was making some videocalls lying on my side in bed, and then first noticed I had to keep my left eye closed during the calls, to avoid eye discomfort. I don’t remember the exact kind of eye discomfort I was experiencing back then. But I think it was the same as it is now – an eye muscle discomfort that was identical to the aforementioned inner thigh myalgia/spasticity. Also an eye burning.
January 2020:
· I learned about “drug withdrawal syndrome” and raised some of the meds (aripiprazole, paroxetine) back up while reducing biperiden further. This, IIRC, removed all eye problems for the time being. It also improved my leg problems a lot. Note that biperiden is an anticholinergic so it can cause dry mucuous membranes including dry eyes (especially when taken in combination with aripiprazole).
April 2020:
· Switched from paroxetine to escitalopram. Started tapering escitalopram and aripiprazole down by about 10% a month (exponential taper).
July 2020:
· Accidentally took a double dose of escitalopram (36mg which is an enormous dose). My heart ached for a week afterwards, and around this time, my past eye problems returned.
August 2020:
· Started taking baclofen (2x10mg) again; it gave me a burning feeling in my eyes, and screen strain. Well, the screen strain might have been very related to the escitalopram overdose of July as well. Went down to 2x5mg baclofen as was planned by my doctor from the beginning. This eased the eye symptoms proportionally.
· Tried washing my eyelids with dish detergent when they felt dry (don’t ask me how I got that dumb idea… 
) and this sensitized my eyes to stuff like detergent preservatives (methylisothiasolinone etc) and worsened the screen strain. Switched to hypoallergenic preservative-free detergents/shower gel/etc, which helped.
September 2020 – present:
· Tried reducing the escitalopram by a tiny amount (e.g. 1% or 3%) on a number of occasions. Every time, my screen strain got worse, and updosing it back did not make it better.
· Overdid my screen time limit (self-imposed) on about 3 occasions (I call it “screen binging”) and every time, my screen time limit got shorter. (i.e. I could tolerate shorter periods of screen usage).
· Got diagnosed with “dystonia” (no mention of “tardive” or “generalized”, just “dystonia”) wrt my whole-body myalgia/spasticity. I think this dystonia is a primary cause of my screen strain too.
Seagull My personal opinion on this issue is that the flickering is altering our natural brain wave frequency. Staring at a flickering light induces corresponding and detectable pulses in brain activity. In a typical person, serotonin neurons will act to inhibit these pulses and keep parts of the brain not involved with visual processing from synchronising.
Is this still your opinion @Seagull? We've seen SSRIs help some people with flicker on here. I wonder if that supports the theory here?
