Severe Sensitivity to Light Emitted from LED-Backlit Displays

[MagnuM]

New poster here! This looks like a wonderful and supportive community, so I already give my big thanks to those that made it all happen, including the Chief Blur Buster! =p

I'm hoping for a really smart person (or at least way smarter than me!) to help me connect the dots on this conundrum I've been trying to solve for over twelve years now:

Excitement was high at the end of 2011 as I dropped multiple grand on a sweet new gaming rig and a Samsung SyncMaster S24A850DW LED monitor! These LED-backlit displays were new to the market and looked like the next generation of flat panels to succeed the first generation flat panel displays (CCFL-backlit LCD)

However, the second I booted up this new computer, there was something about it the second the monitor was turned on that my body absolutely hated. The screen felt extremely bright, and was causing instant pain behind the eyeballs. It was like turning on my iPhone flashlight and putting it right up next to my eyeballs. Turning the brightness down to 0% didn't seem to help much either. On top of that, I felt a "queasiness", almost like the effect of eating something bad and what it does to your GI system, but this symptom felt like it was coming from my neurological system. Things never got better, and I put this new computer in the closet and pulled my old one out of there and that's the way things remained for a year!

Until I decided to try again one day and take my old monitor (4:3 LCD CCFL-backlit monitor) and throw it on the new computer as an experiment. I was absolutely fine with it. It wasn't the computer itself, it was the display! I completed the experiment by taking the new monitor, and throwing it on my old system. Those neurological migraine-inducing effects didn't take long to hit!

Later at work, some colleagues were given these newer LED-backlit displays, and they were causing the same reactions in me! I could only work deskside with folks that had the older CCFL-backlit displays. I was given a Dell U2410 for work, and I liked it and it seemed to work for me if I kept it at 0% brightness, and I bought the same same monitor for myself to use at home as well. Some of these strange light-sensitivity symptoms would return if I upped the brightness on my Dell U2410 though, but nothing compared to the newer LED monitors.

So, that's where things have sort of sat for the last decade plus. Here I am still stuck in the past in the 2000s on older style CCFL-backlit displays, because they are "known good" for me. It seems like I have had to sit out for an entire technology cycle here and wait for some new screen display technology to arrive.

I'm wondering if that time is now with the introduction of OLED displays. Is there something inherently different about the way they work that might work for me? I can't figure out exactly what my system despises so much about LED-backlit computer monitor light when viewed from an arms-length distance.

The most comfortable display I have ever laid eyes on in history are those plasma TVs that used to compete with LCD TVs in the 2000s. Are there any modern display technologies most like plasma? Quantum Dot perhaps (QD-OLED)?

Is there anyone that can shed some light about all this (at least light that won't give me a migraine! =p)

[kyube]

Excitement was high at the end of 2011 as I dropped multiple grand on a sweet new gaming rig and a Samsung SyncMaster S24A850DW LED monitor! These LED-backlit displays were new to the market and looked like the next generation of flat panels to succeed the first generation flat panel displays (CCFL-backlit LCD)

However, the second I booted up this new computer, there was something about it the second the monitor was turned on that my body absolutely hated. The screen felt extremely bright, and was causing instant pain behind the eyeballs. It was like turning on my iPhone flashlight and putting it right up next to my eyeballs. Turning the brightness down to 0% didn't seem to help much either. On top of that, I felt a "queasiness", almost like the effect of eating something bad and what it does to your GI system, but this symptom felt like it was coming from my neurological system. Things never got better, and I put this new computer in the closet and pulled my old one out of there and that's the way things remained for a year!

Until I decided to try again one day and take my old monitor (4:3 LCD CCFL-backlit monitor) and throw it on the new computer as an experiment. I was absolutely fine with it. It wasn't the computer itself, it was the display! I completed the experiment by taking the new monitor, and throwing it on my old system. Those neurological migraine-inducing effects didn't take long to hit!

Later at work, some colleagues were given these newer LED-backlit displays, and they were causing the same reactions in me! I could only work deskside with folks that had the older CCFL-backlit displays. I was given a Dell U2410 for work, and I liked it and it seemed to work for me if I kept it at 0% brightness, and I bought the same same monitor for myself to use at home as well. Some of these strange light-sensitivity symptoms would return if I upped the brightness on my Dell U2410 though, but nothing compared to the newer LED monitors.

So, that's where things have sort of sat for the last decade plus. Here I am still stuck in the past in the 2000s on older style CCFL-backlit displays, because they are "known good" for me. It seems like I have had to sit out for an entire technology cycle here and wait for some new screen display technology to arrive.

I'm wondering if that time is now with the introduction of OLED displays. Is there something inherently different about the way they work that might work for me? I can't figure out exactly what my system despises so much about LED-backlit computer monitor light when viewed from an arms-length distance.

The most comfortable display I have ever laid eyes on in history are those plasma TVs that used to compete with LCD TVs in the 2000s. Are there any modern display technologies most like plasma? Quantum Dot perhaps (QD-OLED)?

Is there anyone that can shed some light about all this (at least light that won't give me a migraine! =p)

Could you list out the exact display models which worked for you?
If you've only tried early LED LCD's (YAG phosphor / classic WLED, as opposed to CCFL) for a decade, then you've missed on a lot of advancements which occured in the LCD monitor market.

The biggest issue being that the early LCDs are known to have severe low Hz PWM dimming light flicker.

[MagnuM]

Sure thing! Thanks for your reply!

The stereoscopic effect of that Samsung SyncMaster S24A850DW I had in late 2011 was absolutely insane. At 0% brightness and doing the pencil wave on a white background, you could clearly see like 10 different pencils that all looked equally sharp to each other. It was insane!

But what threw me off is my colleagues at work that were given LED monitors that gave me instant symptoms did not seem to use PWM - so it's possible that PWM is a red herring for my unique problem. It probably doesn't help though.

Here is the list I have maintained for displays that give me immediate symptoms. We're talking "might as well stare into my iPhone flashlight"

LED Monitors That Hurt Eyes

- Samsung SyncMaster S24A850DW
- Dell P1913
- Dell U2413
- Dell U2713H
- HP Pavilion 7265ngw (laptop)
- BenQ GW2470-T
- LG 22MK(BK)400H
- Dell Latitude 5421 (laptop)
- Dell Latitude 5431 (laptop)

What's fascinating though is that I have found some tolerable LED displays in the last 2-3 years that are pretty close to my Dell U2410 (CCFL) daily driver when it comes to comfort, and I can't understand why.

Tolerable LED Computer Monitors

- Asus VG27AQ
- Samsung LS24DG30X (using right now to write this post)

The two monitors above do not use PWM. However, I bought one of the first PWM-free LED monitors to hit the market in late 2013 (BenQ BL2411PT). My verdict was that it was a lot better than the Samsung SyncMaster S24A850DW that I couldn't even look at for more than a couple minutes, but I could tell my eyes/brain still really didn't like looking at it.

My currently leading theory is that my eyes/brain don't like any displays that have that sharp spike in the blue spectrum, and prefer a more balanced color spectrum. I don't want to bias anyone trying to help me figure this out though.

[kyube]

The stereoscopic effect of that Samsung SyncMaster S24A850DW I had in late 2011 was absolutely insane. At 0% brightness and doing the pencil wave on a white background, you could clearly see like 10 different pencils that all looked equally sharp to each other. It was insane!

But what threw me off is my colleagues at work that were given LED monitors that gave me instant symptoms did not seem to use PWM - so it's possible that PWM is a red herring for my unique problem. It probably doesn't help though.

Here is the list I have maintained for displays that give me immediate symptoms. We're talking "might as well stare into my iPhone flashlight"

LED Monitors That Hurt Eyes

- Samsung SyncMaster S24A850DW
- Dell P1913
- Dell U2413
- Dell U2713H
- HP Pavilion 7265ngw (laptop)
- BenQ GW2470-T
- LG 22MK(BK)400H
- Dell Latitude 5421 (laptop)
- Dell Latitude 5431 (laptop)

What's fascinating though is that I have found some tolerable LED displays in the last 2-3 years that are pretty close to my Dell U2410 (CCFL) daily driver when it comes to comfort, and I can't understand why.

Tolerable LED Computer Monitors

- Asus VG27AQ
- Samsung LS24DG30X (using right now to write this post)

The two monitors above do not use PWM. However, I bought one of the first PWM-free LED monitors to hit the market in late 2013 (BenQ BL2411PT). My verdict was that it was a lot better than the Samsung SyncMaster S24A850DW that I couldn't even look at for more than a couple minutes, but I could tell my eyes/brain still really didn't like looking at it.

Thank you for listing out your panel history.
I was curious whether you tried any modern LED, since a vast majority of LCD's today are PWM-free for at least a decade now.
Do you have any symptoms on your current Samsung display? I'm confused as to how you can use it, while also having symptoms with LED-based displays...
You're correct about PWM. Even if it is a "red herring", one should avoid it all cost as the human nervous system dislike any type of light flicker.
Why exactly have you swapped off the VG27AQ? It should offer a a better user experience due to the better pixel density.

The general rule of thumb when purchasing a display is:
Buy the highest refresh rate & resolution combination which is within budget of a user.
As a point of reference, our eyes can easily see +20 000Hz and notice sharpness possibly even past 32" 8K (+275ppi)

My currently leading theory is that my eyes/brain don't like any displays that have that sharp spike in the blue spectrum, and prefer a more balanced color spectrum. I don't want to bias anyone trying to help me figure this out though.

That is easily "fixable" by enabling Windows Night Light or using 3rd party solutions such as LightBulb
D55 is your friend in this regard

[MagnuM]

Yes, the more modern LEDs seem to be a lot better than the older ones. I remember keeping an iPhone 6S+ for nearly 9 years because I was too scared to upgrade it. I eventually just rolled the dice and bought an iPhone 15 last October to see what happened. To my amazement, it seemed a bit easier on the eyes than my old trusty iPhone 6S+, and the iPhone 15 has an OLED screen. I used this phone ever since October thinking it was PWM-free the entire time, but last Wednesday, I discovered that it actually does use PWM at low brightnesses.

I do have symptoms on the current Samsung, yes. The second I lay eyes on it, I get a pinching sensation behind the eyeballs, and the back of my neck tightens up. It's as if it's some sort of stimulating light or something, or that my brain has some weird overstimulation issue. Unlike some other very problematic LEDs, it doesn't seem to deteriorate into a very sharp migraine (or at least, it happens a lot slower). I seem to get these eyeball pinching symptoms on all LED computer monitors (including the VG27AQ), and the difference is just the varying degree for which it happens. My Dell U2410 also uses PWM, but since it's a CCFL, I believe its duty cycle is much more smoothed out, making it possible that it's imperceptible to my nervous system. I still have not found a monitor more comfortable than my Dell U2410 at 0% brightness.

Oh yes, I warm the colors as well to help. I heard using software for this isn't nearly as good as physical filters like screen protectors or glasses with tint on them. I'm just so curious as to the medical cause of the peculiar sensation I have in my nervous system when I look at problematic displays. I can always go back to my trusty Dell U2410 CCFL LCD at any time, but I would eventually like to join everybody else and have the ability to enjoy the modern screens of today!

[kyube]

Yes, the more modern LEDs seem to be a lot better than the older ones. I remember keeping an iPhone 6S+ for nearly 9 years because I was too scared to upgrade it. I eventually just rolled the dice and bought an iPhone 15 last October to see what happened. To my amazement, it seemed a bit easier on the eyes than my old trusty iPhone 6S+, and the iPhone 15 has an OLED screen. I used this phone ever since October thinking it was PWM-free the entire time, but last Wednesday, I discovered that it actually does use PWM at low brightnesses.

I'm somewhat hesitating to recommend you a phone (AM)OLED display (if you are even searching for that), due to PWM light dimming flicker affecting all humans to some extent (whether they perceive it or not)

I do have symptoms on the current Samsung, yes. The second I lay eyes on it, I get a pinching sensation behind the eyeballs, and the back of my neck tightens up. It's as if it's some sort of stimulating light or something, or that my brain has some weird overstimulation issue. Unlike some other very problematic LEDs, it doesn't seem to deteriorate into a very sharp migraine (or at least, it happens a lot slower). I seem to get these eyeball pinching symptoms on all LED computer monitors (including the VG27AQ), and the difference is just the varying degree for which it happens. My Dell U2410 also uses PWM, but since it's a CCFL, I believe its duty cycle is much more smoothed out, making it possible that it's imperceptible to my nervous system. I still have not found a monitor more comfortable than my Dell U2410 at 0% brightness.

I believe both of these displays you've mentioned are using the classic WLED (YAG phosphor) backlight, have you experimented with wide-color gamut ones? There are 2 types of WLED backlight on the market right now: KSF/PFS ("NanoIPS") and QD ("Quantum Dot")
Perhaps they might ease or eliminate your symptoms.

It's difficult to give you a concrete recommendation, as most display reviews are very shallow in nature in terms of troubleshooting light flicker sources in a display (e.g.: brightness fluctuations in G2G RT curves, VRR flicker curve), potential dithering methods (static, spatial, FRC... mentioned here) which may trigger symptoms & how color intensity impacts humans & other possible phenomena.
If you want to go down the OLED display route for a desktop, make sure to go for RGWB OLEDs (1440p 480hz, e.g.: LG 27GX790A, Inzone M10S). Their text rendering performance is better than QD-OLED, when on Windows.
The other alternative is 1440p 360hz (e.g.: FO27Q3, AW2725DF, XG27ACDNG, MSI 271QRX / 271QPX) or 4K 240Hz QD-OLED (AG276UZD, XG273-4K-OLED etc.)

It's sadly a matter of trial & error, from what I'm aware...
There are some general guidelines, which I think everyone should follow, such as:
- Little to no light flicker is best (in all possible scenarios – static or moving content)
- Yellow (~2700k) to red (<1000K) screen color temperature towards the night to ease the process of melatonin production, one of the strongest antioxidants in our body.
- High CRI ambient lighting (perhaps even incandescent-based light sources)
- x-200cd/m² is generally a nice brightness zone to be in, depending on light coming into room.
(x = lowest possible setting on display, ideally 10-20cd/m²)
- Sunlight is essential (at early hours of the day and towards the night) for human health & longevity.

I've benefited from a few inserts which are found in this blog, perhaps you might too.
All of this above assumes you've got all physiological & psychological variables in check.

Oh yes, I warm the colors as well to help. I heard using software for this isn't nearly as good as physical filters like screen protectors or glasses with tint on them. I'm just so curious as to the medical cause of the peculiar sensation I have in my nervous system when I look at problematic displays. I can always go back to my trusty Dell U2410 CCFL LCD at any time, but I would eventually like to join everybody else and have the ability to enjoy the modern screens of today!

I haven't seen any long-term studies which have dabbled their toes into this topic yet...
It seems to me that ophthalmology is somewhat falling behind in this regard..

[MagnuM]

I so much appreciate you taking time and effort to help me try to solve my screen sensitivity issue, kyube! Apologies for my delay in response - I was testing out some new monitors over the past month, and I wanted to give them each some "bake in" time to be more confident in the results.

It is so bizarre how specific my issue is: It seems limited to just computer displays. I don't have this issue with cellphones (currently on iPhone 15, previously iPhone 6S+, iPhone 5). I don't have this issue on TVs (still using Samsung LN40A750R1F 40" LCD from 2008, but I can watch movies at my friend's houses who have LED TVs). I don't have this issue at the movie theater. However, I do have these seemingly neurological light-sensitive issues almost instantly when looking at most modern computer monitors. I'm stuck on all the first-generation LCDs flat panel monitors from 2005 - 2010 that were backlit with Cold-Cathode Fluorescent Lamps (CCFL).

... kinda... I did mention that if I up the brightness on my trusty known-good daily driver (Dell U2410 CCFL) up past 0%, these same type of light-sensitive issues will start immediately around 50% brightness and higher. This was definitely one of the brightest LCD monitors when it first hit the market in 2009 at around 400 cd/m2 max brightness.

The issue I had with the first LED-backlit monitors that hit the market was that 0% "wasn't dim enough" seemingly for me. I would get these terrible "light is too bright symptoms" in my eyes, despite the monitor appearing so dim that it was hard to see much on it. Harsh PWM was probably a contributing factor to my neurological insults looking at these things at the time, but even PWM-free LED-backlit monitors at work that my colleagues had the backlight cranked up on would cause severe headaches within minutes/seconds. In fact, it seemed like every LED-backlit display caused these severe issues for me for an entire decade. I captured many of these models over time.

Monitors Causing Severe Headaches Within Minutes/Seconds - (2011 - 2021)
- Samsung SyncMaster S24A850DW
- Dell P1913
- Dell U2413
- Dell U2713H
- HP Pavilion 7265NGW (laptop)
- BenQ GW2470-T

The list above would generate pretty intense symptoms that could not be pushed through. Toughing it out just made the symptoms worse, and increased the amount of days it would take for the sharp headache to dissipate. We're talking minutes/seconds of exposure leading to very long recovery times. Once I tried to push through 30 minutes looking at one of the Dells in the list above to have a very sharp migraine-like light sensitivity headache that lasted for 4 full days.

Then something strange happened in 2022. I suddenly found many monitors manufactured since then to be much more tolerable. I have to put this one in a new tier list:

Monitors Causing Mild Headaches Within Minutes/Seconds - (2022 - present)
- Asus VG27AQ (W-LED IPS panel)
- Samsung LS24DG30X (W-LED VA panel)
- MGI MAG 271QPX (QD-OLED panel)
- Dell P2425 (W-LED IPS panel)

I still get the symptoms rather instantly when I look at these monitors above, but it seems like my neurological system is able to "push through" them over exposure rather than the symptoms worsening to a full-blown migraine headache. One could question if this is a good idea to force your system to be doing this daily or not.

Just today before making this post on Saturday, I had a 15 hour break from screens after the work week ended and I went golfing. I'm currently testing a Dell P2425 that I unboxed on July 1st of this week. I get these symptoms immediately after turning on the monitor to start my session every day:

- Sharp ache / pinching behind the eyes
- Feeling of overstimulation, or feeling on-edge
- Tight temples
- Neck tightness
- Brain feels slower, busier, overworked, overwhelmed

But if I tough through the above for about a period of about 15 minutes, the symptoms seem to numb, and I don't notice it as much. If I walk away for an hour and come back though, then everything sort of resets. This is almost the opposite from the earlier list where pushing through makes things worse.

In-between my last reply over the past month, I tried a quantum dot for 2 weeks (MGI MAG 271QPX). What an absolutely gorgeous monitor! It was just so stunningly sharp with such beautiful colors on the standard settings! It pained me to return it, because I was finding that the more mild symptoms above were still happening. I was able to cut the symptoms down a lot by activating the hardware blue light filter in the OSD, and changing the color temperature to "Warm", but then I wondered what's the point of having such an expensive color-accurate monitor if I have to do these work-arounds?

Very similar with the Dell P2425. During an on-site visit at work last month, I decided to try out one of the new line of monitors they ordered in just to see what happened. It wasn't bad after using it for a few hours. Definitely noticed that pinchy/cramping feeling in the eyes, but not bad. So I ordered one for home and I'm trying that out.

I noticed something interesting on their official webpage for the monitor:

https://www.dell.com/en-ca/shop/dell-24 ... ccessories

If you scroll to the section titled "Improved ComfortView Plus" with the sub-caption of "Reduces harmful blue light emissions to ≤35%, for all-day comfort without sacrificing color.", they have a video there that shows that they have moved the big blue spike on W-LED color spectrums more towards green and longer wavelengths without sacrificing color quality. Is this even possible? If that's what's going on, I wonder if that's what my eyes/brain seems to be more OK with? I still get symptoms on the default settings, but changing the color temperature to "Warm" and using Windows Night Light at around 25% does seem to noticeably cut down symptoms.

You know, in my 13.5 years of having this specific problem, I only ever found one other user that seemed to describe the same symptoms. It's the user Jason38 here on the Blur Buster Forums. I believe they may have also been over at LEDStrain.org too. They said they can only use modern flat panel monitors if they wear aggressive orange SCT construction glasses like these:

https://www.globalindustrial.ca/p/s1933 ... aignId=T9F

I ordered the same glasses and have them, and I definitely notice a large reduction of symptoms. However, the orange tint is so aggressive that lots of contrast can be lost sometimes, and it can be hard to read some text. Pure yellow can't even be seen because the whites are color-shifted to be so yellow that it camouflages, lol! The user said they could use computer monitors as long as they were wearing these, but the reason why they kept posting was to try to find a solution that could allow them to ditch the glasses.

And they did, but it doesn't make sense to me. They said they tried a ViewSonic XG270 (W-LED IPS panel), and it was the smoking gun. They claimed to be able to use the monitor 16 hours a day, every day, without the glasses. They haven't posted since 2022, because they likely just went along their way and enjoyed life after that with this just being a distant nightmare of history. They also had this sensitivity problem for well over a decade. Good for them, but I admit I'm a bit jealous, haha!

Perhaps this is what I could try next. I could just buy the exact same monitor they did. However, do we suffer from the exact same source issue? Their issue seemed even more severe than mine. I don't have to wear dark orange SCT glasses to tolerate some of these more modern displays. Looking at the specs of this monitor on DisplaySpecifications.com, I see nothing about this ViewSonic XG270 that jumps out at me that could be a difference maker. Sure, this model doesn't use FRC (Frame Rate Control - a.k.a. temporal dithering), but neither did my MGI MAG 271QPX quantum dot, yet the symptoms still hit.

So I totally agree with you that this process seems completely random and almost trial-and-error based. I believe the Chief Blur Buster suggested the same. Everyone will just have to try 10 different monitors about as different from each other as it gets, and then try to narrow down their issue through the process of elimination. Gosh, this is going to make future monitor shopping an absolute nightmare if we can't nail down the root cause source of the issue!

[kyube]

-snip-

Thank you for the extensive write-up.
I'll try addressing a few points you've made one by one:

The issue I had with the first LED-backlit monitors that hit the market was that 0% "wasn't dim enough" seemingly for me.

That is sadly the case which a majority of reviewers for many years up until recently have omitted.
Thankfully, the situation is a lot better in this regard nowadays (e.g: RTINGS measures minimum brightness)

Monitors Causing Mild Headaches Within Minutes/Seconds - (2022 - present)
- Asus VG27AQ (W-LED IPS panel)
- Samsung LS24DG30X (W-LED VA panel)
- Dell P2425 (W-LED IPS panel)
- MSI MAG 271QPX (QD-OLED panel)

That is quite a line-up of displays you've tried.
Note how each one of them has a high blue spike

- Tight temples
- Neck tightness
- Brain feels slower, busier, overworked, overwhelmed

This might be somewhat odd to you that what I will mention, but have you explored doing neck exercises?
Basic flexion & extension exercises without adding additional weight, every 2-3 days isn't that bad to incorporate in one's routine.
E.g.: 3 sets of 20 reps

I was able to cut the symptoms down a lot by activating the hardware blue light filter in the OSD, and changing the color temperature to "Warm", but then I wondered what's the point of having such an expensive color-accurate monitor if I have to do these work-arounds?

If you scroll to the section titled "Improved ComfortView Plus" with the sub-caption of "Reduces harmful blue light emissions to ≤35%, for all-day comfort without sacrificing color.", they have a video there that shows that they have moved the big blue spike on W-LED color spectrums more towards green and longer wavelengths without sacrificing color quality. Is this even possible? If that's what's going on, I wonder if that's what my eyes/brain seems to be more OK with? I still get symptoms on the default settings, but changing the color temperature to "Warm" and using Windows Night Light at around 25% does seem to noticeably cut down symptoms.

This part caught my attention the most.
The prevalence of direct blue light exposure from monitors is definitely somewhat detrimental to the health of our eyes.
You should definitely experiment with blue light filters.
I wouldn't consider it a "work-around" at all, I find that all displays should have an automatic ~5000–5500k to lower than 1000k temperature sensor for use during the night.

I ordered the same glasses and have them, and I definitely notice a large reduction of symptoms. However, the orange tint is so aggressive that lots of contrast can be lost sometimes, and it can be hard to read some text. Pure yellow can't even be seen because the whites are color-shifted to be so yellow that it camouflages, lol! The user said they could use computer monitors as long as they were wearing these, but the reason why they kept posting was to try to find a solution that could allow them to ditch the glasses.

I've personally found that such "blue light blocking" glasses alter the natural sharpness of my eyesight.
Hardware solutions (through OSD or external filters) or software solutions (Windows Night Light, Lightbulb etc.) seem to be better
Here's a list of such glasses, if you're interested:
https://optimizeyourbiology.com/blue-blocker-database

This topic might also interest you:
https://optimizeyourbiology.com/block-b ... -on-iphone

Here's a topic on here discussing the efficacy of blue light filters:
viewtopic.php?t=9211

And an RTINGS article:
https://www.rtings.com/monitor/learn/blue-light-filters

And they did, but it doesn't make sense to me. They said they tried a ViewSonic XG270 (W-LED IPS panel), and it was the smoking gun. They claimed to be able to use the monitor 16 hours a day, every day, without the glasses. They haven't posted since 2022, because they likely just went along their way and enjoyed life after that with this just being a distant nightmare of history. They also had this sensitivity problem for well over a decade. Good for them, but I admit I'm a bit jealous, haha!

I would avoid 27" 1080p displays like the plague. That particular display shouldn't be on your radar. The subpar pixel density is a far bigger eye ergonomics concern than anything else. It's a standard W-LED backlight.
A few of the eye-strain communities online seems to have a tendency to think that every modern panel is bad (out of ignorance on how they differ) and resort to really archaic density + refresh rate targets, which is not the right approach.

Gosh, this is going to make future monitor shopping an absolute nightmare if we can't nail down the root cause source of the issue!

I don't think finding a display for you is gonna be difficult at all.
I can give you a few general tips for hunting down a display:
- Stick to 24" 1440p or higher density (gets even more important if your desk is a shallow depth)
- Find the highest refresh rate panel with said specifications.

This chart might be helpful to figure out which density you need for your desk depth:

30 ppd — 20/40 vision; poor vision
60 ppd — 20/20 vision; below average vision
80 ppd — 20/15 vision; average vision limit [1], [2]
120 ppd — 20/10 vision; practical upper limit of visual acuity
150 ppd — theoretical upper limit of visual acuity [3]

Source of data: https://phrogz.net/tmp/ScreenDensityCalculator.html

I'd usually recommend the AOC Q24G2A, as it uses the a classic WLED backlight.
But in your case, the AOC's ability to adjust the blue peak is implemented subpar.
One has to resort to SW solutions or external screen protectors, hence I don't think it's a good idea to go for it...

I'm certain that your theory of of the sharp blue light affecting you is very likely true.
Take a look at the Zaid's blog I've mentioned in my previous post, it has a few topics in regards to light & eye health

To some extent, this topic is definitely trial & error, but one can always rely on reviews to nail a few variables down (total luminance levels at different % values, backlight SPD graphs etc.)
In particular, about your talk of the blue light emission of your displays.
https://pcmonitors.info/articles/the-ev ... acklights/ — this particular article talks about the history of LCD monitors and how their SPD graphs have evolved over time.

Let's take a look at typical "CCFL" LCD's, W-LED LCD's (YAG phosphor), WCG W-LED LCD's (KSF/PFS and QD-based)
(order of images is as mentioned above, taken from the PCMonitors article)









As for your CCFL monitor:
https://tftcentral.co.uk/reviews/dell_u2410.htm
https://hardwarecanucks.com/forum/threa ... iew.43469/
(slightly different values)

It seems that your prefer luminance levels of ~100cd/m2, which is the most common target being recommended.
You can use phone apps to evaluate luminance levels of displays you use to try & make them equal.
The process is shown here: https://youtu.be/avJTz1JhkR4?si=QPstuOKUMzMpIC1f&t=409

[MagnuM]

You are being tremendously helpful kyube, and you have my utmost gratitude in sharing your wealth of knowledge that you have gained! You are the smart person that I was seeking when I started this thread, as you certainly know a lot more about this stuff than I do! You are helping both me and any potential lurkers that are reading this thread.

Health issues are notoriously difficult to solve (and expensive!) There are potentially other details I have been leaving out as to not thicken the plot any further. I'm also trying my best to keep my posts detailed but not overly long, but the lengthiness seems to occur anyway!

Ophthalmologists are some of the most highly educated medical specialists there is, but when it comes to this particular issue with computer screens, I haven't seen them help one single person in my decade plus of trying to get to the bottom of this issue. They tell all sufferers the same thing, including me: "you have dry eyes". That has never helped anybody. I wouldn't say I have dry eye symptoms, and I don't think it is contributing to my light sensitivity.

I just had my annual eye exam with my optometrist on Friday, and he knows all about my screen sensitivity and has been trying to help me for some time now. He pointed out that I have seen some of the best eye specialists in the city about my condition, and they all state that my eyes look quite healthy. With correction, my optometrist was astounded that I could achieve 20/10. That might even be too good. I might have to believe him and everyone else I've seen that my eyes are fine, and that we've been all looking in the wrong area the entire time. I think the issue is in the brain when it comes to my light sensitivity from screens.

I like how you focused on what makes a CCFL-backlit monitor so different than an LED-backlit monitor, and then you showed the PCMonitors.info spectrometers showing the differences between each. It was quite eye-opening! I didn't know that CCFLs have their big spike in the green part of the spectrum. I thought they had a similar shape on the blue side of things, just not as sharp and intense of a spike.

My work-around solution to go running back to my Dell U2410 CCFL is always present for me, but I know that it's a solution that won't last forever. It's also not a perfect solution either. As mentioned, if I reset the settings of the monitors back to default settings of 50% brightness and 50% contrast, it will cause the pinching eyeballs sensation. I will deliberately do this when working with color-sensitive work and just put up with the pain for the few minutes/hours I need to before reverting the brightness back down to 0%. The monitor also has PWM flicker, which would be at its highest at 0%, but since there is a little bit of glow that CCFL has during the "off" period of the duty cycle, it's possible that my neurological system isn't noticing it (as much!)

But as you correctly mentioned, minimizing flicker as much as possible should be the goal. I can't see a situation where flicker wouldn't be detrimental to somebody's neurological system. Despite how good this Dell U2410 has been for me when it comes to the neurological effects of the backlight, I still have problems with chronic eye strain on it that has ended me up in binocular vision therapy twice (2012 - 2014, and March 2025 - present). In my current VT program, I didn't do so great in a 9-week recheck recently, and so we have pivoted towards Syntonac light therapy instead of the traditional eye exercises.

There was one opthalmologist I saw in 2014 that may have been potentially helpful. He said that it's controversial, but that I should look into Irlen Syndrome. I went for a consultation and they suggested I was a positive. However, I was skeptical, because I was using colored filters on printed paper. Well that isn't my problem. I only have problems with computer screens. The practitioner suggested that a blue filter seemed to be doing well for me while reading, but that seems to be the exact opposite to the problem I'm facing. A blue filter would block the long wavelengths like yellow which I don't seem to have a problem with. Irlen Syndrome was considered controversial in 2014 and a decade later seems to be considered bunk (at least according to the Wikipedia article about it).

I'll admit, perhaps the Syntonac light therapy I'm doing now is going to be considered the same. It's hard to find any information about it even. I was given these cardboard glasses with dark blue lenses that only allow blue light in. It is called the "Pi-Omega" filter as seen in this link: https://images.squarespace-cdn.com/cont ... G_0101.JPG". I'm to wear them 7 minutes a day outside every day as a passive treatment. I find it silly but at least my grass has been happy, as it gets water every morning now! One recheck since trying this method is suggesting a slight bit of improvement on vertical heterophoria, but I asked if it could be luck or due to another factor too, and my vision therapist agreed that it's a possibility.

You mentioned that many of the monitors I tried have a "high blue spike". Do you have a bookmarked resource that shows this?

Your comment about focusing on the neck is interesting. I'm quite tall at 6'4", and I think my bad forward head posture was caused the most from being hunched over a laptop with a desk at home that was too low for me back when I was in tech college back in 2003 - 2005. In March of 2006, I once woke up to sudden intense tension headaches that made me feel extremely spaced out - as if I was still dreaming or had slammed multiple shots of vodka quickly or something - when I woke up one random Sunday morning. It turned chronic and has been off/on ever since and I also never have found the cause. However, it's been a lot better in more recent years, and I have focused on trying to sit with better posture at the computer (sitting up straighter, not slumping and rounding my back into the backrest lazily, etc). I've also been working out and trying to improve upper body posture that way as well.

I want to stress that the above is a different type of headache (tension headache) and issue that exists co-morbidly with this one. I left this out initially as to just focus on this LED light sensitivity that creates more of a neurological and instant headache more akin to a migraine. Well, at least I am assuming that the 2006 chronic tension headaches and this 2011/2012 screen sensitivity headaches are different issues...

What's frustrating for me trying to study and research this issue is that I seem to be against the latest science-based studies on the subject. 10 years ago, they definitely thought blue light caused eye strain, and blue blocking glasses were all the rage. Now, the more recent studies suggest that blue light does not cause eye strain, and they think blue light blocking glasses are not helpful for eyestrain. However, the studies do seem to suggest a link between blue light and sleep issues, of which blue light blocking glasses might be a benefit for.

I seem to have the opposite issue. Blue light seems to cause me physical pain and an effect on my nervous system, but it doesn't seem to affect my sleep (as far as I know!)

All I can report is my subjective experience. I've noticed that my eyes/brain do not seem to like looking at a bright white background. Just think of the Google.com homepage (assuming no dark mode enabled or anything). If I warm that white using the Windows Night Light slider, my nervous system instantly feels better doing it. For example, let's say what I feel is similar to what most everyone would respond to a nails-on-the-chalkboard sound from an auditory stance. Warming the colors would be akin to someone filing their sharp nails down somewhat to blunt them before scratching the chalkboard again. It's still harsh, but not as harsh.

What about bright white LED car headlights? Aren't there a lot of people that claim that they are so bloody harsh to look at, and that they could swear that the other driver has their brights on? I'm not sure how people can look at these harsh bright blue-tinted lights and not feel pain or discomfort of some sort from it!

Correct me if I'm wrong, but did CRT monitors generate very little blue light? Those are what I grew up on. Their claim to fame was total blacks and color accuracy, but what about whites? CRT whites always looked rather dull and grey to me. Those whites got whiter and brighter when CCFL LCDs came out, and then whiter (and specifically bluer) still when LED LCDs came out. Perhaps most people are fine with looking at these very bright whites, but my brain always has the desire to dull those whites to make it look more like yellowed aged newspaper!

I have another question about warming the colors too far though. I couldn't imagine going as red-shifted as 1000K as you suggested! That would crash the contrast so far that it seems like it would cause eye strain in and of itself trying to read text because the contrast isn't high enough!

As for your comment on pixel density, I don't think that affects me at all. I always would enlarge text on my Dell U2410 whenever I could, as I found I would get more eye strain if I didn't (the kind that has led me back into binocular vision therapy for a second time). I would have more issues if I'm looking at tiny text at work for extended periods (I'm a SysAdmin as a living and have been for 18 years).

Again, the reason I'm quite sure it's not pixel density is that I want to stress that the very microsecond the monitor backlight hits, my nervous system is insulted equally quick. On a problematic display, I could have the BIOS screen loaded on the computer, hook a monitor up, turn it on, and the second light is emitted, it's a hand-on-the-stove-element equivalent pain response to my visual system. Therefore, I don't see how pixel density would be at play for the light-sensitive issue of mine as part of this thread. Perhaps the other issue of eye strain I have that I'm in vision therapy for, but for the sake of simplicity, I'm just focused on the light sensitivity for now.

So I've talked about myself for a while, but what about you, kyube? What has led you to the health side of the Blur Buster Forums? How did you gain so much knowledge about all this stuff? Pain can be a great motivator, so that was mine (as in trying to get out of pain!). Did you or are you having issues from screens as well? I'm curious to hear your story! Thanks for listening to mine once again!

[MPRT|GTFO]

The screen felt extremely bright, and was causing instant pain behind the eyeballs. It was like turning on my iPhone flashlight and putting it right up next to my eyeballs. Turning the brightness down to 0% didn't seem to help much either.

The second I lay eyes on it, I get a pinching sensation behind the eyeballs, and the back of my neck tightens up. It's as if it's some sort of stimulating light or something, or that my brain has some weird overstimulation issue.

I still get the symptoms rather instantly when I look at these monitors above, but it seems like my neurological system is able to "push through" them over exposure rather than the symptoms worsening to a full-blown migraine headache. One could question if this is a good idea to force your system to be doing this daily or not.

[...]I get these symptoms immediately after turning on the monitor to start my session every day:

- Sharp ache / pinching behind the eyes
- Feeling of overstimulation, or feeling on-edge
- Tight temples
- Neck tightness
- Brain feels slower, busier, overworked, overwhelmed

But if I tough through the above for about a period of about 15 minutes, the symptoms seem to numb, and I don't notice it as much. If I walk away for an hour and come back though, then everything sort of resets. This is almost the opposite from the earlier list where pushing through makes things worse.

I don't experience anything nearly as severe as the worse problems you describe, but I can definitely feel some of the milder things, I've observed what causes it and when (the "when" part not being mentioned much so far), and I think I understand the mechanisms (at an intuitive and popular-science level, I'm not a scientist or a professional in the field) and know what not to push through.

You've already figured out that the color temperature plays an important role. Think about how things happen in nature and the conditions under which humans have evolved. There aren't many natural sources of light. Under daylight the color temperature is mostly around 5000K-6500K (the average temperature of the photosphere of the sun is a constant in that range, but the light that reaches us varies somewhat by conditions). First of all, anything higher than that in nature has got to be some sort of highly energetic event that produces even higher temperatures, such as a lightning or a bolide, both of which could kill you. So it should come as no surprise when the reaction of the human body to such stimuli is negative, one of confusion or distress, even more so if prolonged. I would consider this normal.

As for the fact that many monitor and other device manufacturers push color temperatures above 6500K by default: I really don't think there has ever been any reason other than to try to deceive consumers by the first impression, and by playing on their nervous system. Higher color temperatures give the impression of higher brightness. I've even seen small-time LED lights salespeople spreading misconceptions pointing at the color temperature value and trying to pass off higher color temperature lights as being brighter. Higher color temperatures, as you've also noticed, when seen at sufficient brightness through the eyes, also stimulate the nervous system and increase wakefulness. Apparently such manufacturers and salespeople also count on people more often reacting positively than negatively to the stimulating and wakening effect (at least for a short while). I think it's probably true for most people most of the time, but not for you.

In cases when there has been more to the motivation for choosing a color temperature (like making a standard to actually use) people have come to values such as 6500K or lower. Needless to say, people should always make sure the color temperature of the monitor is configured no higher than 6500K (unless they know what they're doing). And as far as I know, it's okay to go somewhat lower than the most popular standard, with some caveats about 1. color-critical work and cases where consistent colors between devices or materials are needed, and 2. inherently losing contrast for the blue color for a given overall brightness level due to reducing the range of the blue color, and also potentially losing more depending on the way you change the temperature (monitor vs. different software) and the monitor hardware (how many true bits per color, etc). I'm pretty sure the human vision has some mechanism for adjusting to different color temperatures and still perceiving the colors as they are supposed to be. It just takes some time (minutes, somewhat longer than other adjustments like adjusting to low light conditions and back) so if lowering the temperature further at first seems too warm, give it some minutes or an hour before trying again (note the seeming contradiction between the cultural notion of "warm colors" corresponding to lower "color temperature", which is related to the physics concept of lower "black body temperature"; the two things go in opposite directions, so hopefully no one gets confused). I'd not worry too much at this point about losing the goodness and accuracy of the colors. It's probably a good idea to first experiment a little to find a way to consistently get rid of symptoms on any device and then you can try to get the contrast and picture quality back, like a different way to adjust the color temperature and perhaps experiment with increasing the brightness (along with the ambient light for comfort) in order to get a higher range for the blue that way. As a general principle though, I believe one should be trying to get conditions as close to natural as possible, and only if that really does not work should one experiment away from that.

And so far I only mentioned light during the day, but of course during the evening and night the human body expects the color temperature to gradually drop a lot (like what Night Light normally does and what kyube recommended) but also the brightness drops hugely. Thinking of human evolutionary timescales, I guess normal light sources should be considered fires (low temperature, so think of color temperatures below 1400K, and low brightness) and moonlight, which is bluish (higher color temperature) but that's barely bright once in a blue moon And so those happen to be roughly the limits that I find totally comfortable for the night, including not feeling stimulated and not feeling pain behind the eyes. Yes, such low color temperatures and brightnesses are pretty bad for the picture quality (reading is least affected though, unless you want to read blue letters on black or something like that), but I don't know if a better way to achieve that level of comfort during the night even exists. It's a tradeoff between that, and whatever the body's reaction is (which surely differs somewhat between individuals). You can play around to find optimal settings, but once you find them, note that I find it best to stick to the same colors and brightness for the night, every time, because having anything more than one day mode, one transition period and one night mode can itself make things more difficult and uncomfortable for the body.

Basically the normal natural process goes something like this. First, when light of sufficiently high color temperature and high brightness reaches your eyeballs in the morning it starts to stimulate you and prepare you for the day. During this phase I feel a little bit of perhaps what you call pinching behind the eyes, but it's like a really mild exertion and not unpleasant. If I make the transition very fast, like looking right at the sky or a white screen it's a stronger feeling and sometimes it can reach unpleasant levels, but it quickly goes away. So I wonder, would you also feel some of your symptoms if you quickly transition from indoor, low or medium light conditions to looking straight at a bright sky, filling as much of your peripheral vision too, to get a lot of blue light hitting throughout the eyes? If you're comfortable with bright natural light and bright artificial light, I think there has got to be a way to make monitor light similarly comfortable, at least during the day. One thing that may help is to ensure you have sufficient light in your room so that there is not a big difference in brightness or color temperature between your monitor and the background behind it. Also, you never mentioned any difference in symptoms and their severity between daytime and nighttime. I think it may be telling what you'd feel in the middle of the day, using a monitor at a natural color temperature and bright enough to have a good visual contrast, and with room lighting conditions that are not too dark or too warm compared to the monitor.

And then the normal natural process for the body is that light becomes warmer and dimmer during dusk, which is detected through the eyes, sending a signal to prepare for the night. Anything that interferes with that could potentially cause problems, including light conditions that are totally fine during the day (it would be a similar situation as some form of jet lag).

It is so bizarre how specific my issue is: It seems limited to just computer displays. I don't have this issue with cellphones (currently on iPhone 15, previously iPhone 6S+, iPhone 5). I don't have this issue on TVs (still using Samsung LN40A750R1F 40" LCD from 2008, but I can watch movies at my friend's houses who have LED TVs). I don't have this issue at the movie theater. However, I do have these seemingly neurological light-sensitive issues almost instantly when looking at most modern computer monitors.

That is interesting indeed, because there are so many technical similarities between these and a few differences in the way they're used. Monitors are used at a close distance, which causes responses in the eye, but that is similar to phone screens or even reading a book in a brightly lit place, so I guess those responses are not related. The other difference is that typically monitors take up a much wider portion of your field of view. That means a higher amount of light entering the eyes overall, but it also means that the light from far edges of the screen reaches further away from the center of the retina, compared to watching a phone or TV screen. There are some differences in structure and function between different parts of the retina, so conceivably this can play a role. Then again, if you look up at a bright sky it can be even brighter and wider in your field of view, but I haven't seen you mention any symptom from things like that yet. The remaining factor differences are mostly the spectrum, in combination with the large quantity of light. If you want you can try some experiments, such as using a monitor from a very long distance (like taking as wide a FOV angle as a known good TV setup would) and zooming things (through DPI setting, resolution or whatever). Or taking some glasses or glass frames and sticking opaque tape on the periphery (just don't ruin good glasses with tape glue residue ) to artificially reduce your field of view somewhat, and then using limited size windows, turning your head to look at a different place, or leaning back to see the whole screen. Of course those are just experiments, and if there is an interesting result we could try to draw conclusions or figure out something more practical.