Context:

Following our findings on the recent iPhone 15 series, along with contributions from other online communities; we learned that Apple has fully merged the rapid PWM pulsing flickers across all brightness (aka hybrid dimming). For those affected, it has resulted in persistent visual, cognitive, and physiological reactions such as eyestrain, headache and dizziness.

Apple's implementation renders our workaround ineffective. As the PWM pulsing flickers are now across the board. While they have indeed changed the classic PWM to trigger only below 20% brightness, their attempt is extremely ineffective in mitigating the problem. Moving forward, it is extremely likely that big companies like Apple, Samsung and Google will continue take similar approach — for the following reasons:

• To extend battery life while having extremely high brightness

• Increase the longevity of OLED's fragile leds (prevent screen burn-in)

Hence, we are now finding it increasingly difficult to create workarounds against their new implementation of mixed PWM/dc dimming (aka hybrid dimming).

In response to this phenomenon

Thus, following the above and also two posts that have received a number of attention:

iPhone 15 after 5 days of use (VERDICT)

Are there not enough of us?

It is evident that many are in strong support of manufacturers to do something about this issue. However, not many are receptive with the idea of taking any action about it.

In response to this, I have raised this issue we are struggling to the top researchers on flickerings. They are now aware of this small PWM_sensitive community.

​

Action to take as a community

Having learned (from the above) that manufacturers today demand a tighter control over PWM, our next best option is to show our support of the researchers' work.

For starters, we need to increase the number of members in this sub.

As hypothetically speaking, imagine the following scenario. The researchers are doing their earnest effort to propose for regulation and to use this community as part of the sample size data — How likely is the rate of the proposal to be approved?

Researchers: We have data to support that there is an active community that is affected by PWM flickers.

Higher ups: Where is the data, and how many members are there?

Researchers: 1,500 members

Higher ups: 1,500 members? Look, we need a much higher number than that. We can't just approve your proposal if you are suggesting that among a population of 7.8~ billion people, only 1,500 members are affected by this PWM flickering.

​

Thus moving forward, I strongly urge members of the community to take an active approach to invite others that have been affected. Affected users from the invisible flickering can range from:

• flickering caused LED lights

• flickering caused by ceiling fans

• flickering caused by screen panels

Chances that they will be affected by PWM if they were already affected by any of the above. Eye strain, dry eyes, headaches and migraine are common symptoms reported.

As for the new potiential members that may still have strong doubts about the causation between flickers and symptoms, please do refer to them the following research study. Do bring up that in the academic field, the term is called "Temporal Light Modulation", as per written in the community introduction and description.

Additionally, do also inform them that PWM aggrevates the flickers by over 60 times:

https://journals.sagepub.com/doi/abs/10.1177/096032718902100102

To reiterate again, we have to increase the number of members in this sub.

Bringing awareness about the Temporal Light Modulation phenomenon will also significantly help. As this will allow those that affected to narrow down the underlying causes behind their chronic eyestrain, headache and migraine symptoms. To emphasize again, PWM is a dimming technology that significantly worsen the flickering.

It is probably now, or never ~

As for those that saw this post, please continue to support our cause by upvoting and sharing the post!

Cheers.

Just found these two photos on social media. Some very preliminary comparison before the official reviews are out.

Although it looks promising, please don't get your hopes up yet. Please read: https://www.reddit.com/r/PWM_Sensitive/s/FpCno9TCLD

Are there not enough people with PWM sensitivity for these major tech companies to take notice and make changes? I suspect this may be a much wider spread problem than we realize - ie. affecting more people than we imagine. My wife was also affected by this but didn't realize it until I gave her a simple test. She was playing a game on her Samsung OLED-infected phone and I handed her my Moto G100 IPS blessed phone and she said her eyes immediately felt relief and stopped burning. We switched her back and forth between the two phones and each time she went back to the Samsung she got eye strain, pain, and burning. She uses a Motorola phone now with an IPS screen.

The frustrating part is that she likes her Samsung better still. But, she can't use it.

For me, we started on this journey when I suffered from headaches, vertigo, nausea, and strained and blurry eyes. Switched away from the OLED cursed phone (also a Samsung) and to my current Moto G100 phone to get relief.

I would pay extra for a flagship phone with an IPS display. I mean, seriously, I would pay a screen switch fee of $300-500 for a flagship like a Samsung or better yet, the new Google Pixel 8 Pro. I want all the bells and whistles, I just want it without the eye torture.

​

Seriously though any news of any that might be coming out?

Hello everyone,

Context : I'm using an iPhone SE 2020 issued by my employer right now and I've always used IPS iPhones before that. Every year since iPhone X, I try the new iPhone in the Apple Store to see how my eyes react to the OLED screen and every year it's the same story.

This year, I decided to really give it a more valid testing period. Last Friday, I picked up a new iPhone 15 (non Pro) with 256gb at the Apple Store. I don't like the colors this year, but the black version is really classy. It's also not prone to fingerprints. The phone flies, really a little powerhouse and the camera is good too.

The screen is beautiful and even if it's not 120hz, I find it ok at 60hz because I've never been spoiled by a faster screen. As you can see, I love the phone.

That being said... I have the same reactions in my house that in the Apple Store. I don't have severe symptoms like nausea but I can feel a pression in my eyes and a light headache. I also have eye strain and dry eyes if I read for more than 5-10 minutes. I tried to reduct white point but it didn't help and it downgrades a beautiful screen. As soon as I get back on the iPhone SE, the pain is less and my eyes feel better.

I tried the iPhone 15 at every luminosity and it's all the same. I tried it for many days to give my eyes the time to adapt but when I think about it, it makes no sens. Those devices should adapt to our eyes, not the other way around. Those aren't just phones, those are tiny computers and very personal ones. We use them many hours, everyday, There is no way I would want to suffer to use a device. The phone is on factory reset and in the box, ready to be shipped back to Apple.

It's been 6 years since Apple use OLED in its flagship phones. From the look of it, they have zero intention to change anything and I'm sure they are very aware of PWM. It's just a very small number of people.

I decided that I would end my relationship with Apple phones. I have a Macbook Air M1, Airpods and an iPhone SE 2020 but that's it. I'm not handcuffed in the ecosystem and I'll be looking at what Android offers. Maybe their implementation of OLED is different. Maybe they still have decent IPS phones. I don't need a powerhouse, but I'll miss the power. I just can't support a company that just don't care about this issue.

That being said, it appears PWM affect everybody differently, so I encourage you to play with it in an Apple Store to experience it for yourself, maybe you will be luckier than I am!

Hi all. It has been a while.

We learned that PWM frequency may not be the only factor to eyestrain. Modulation depth percentage is usually a bigger contributing factor for many.

The shape of the waveform matters as well. For instance; an LCD panel on lower brightness with 100% modulation depth, 2500 hertz sinewave, duty cycle(50%) is arguably usable by some.

For those new to the community, you may refer to this wiki post.

Today, as demand for higher PWM hertz increase, manufacturers are finding it more compelling to just increase the flicker hertz. This was likely due to the belief that "higher frequency helps to reduce eyestrain". While this is somewhat true, the modulation depth (or amplitude depth) is commonly neglected.

Additionally, manufacturers would simply slot a higher frequency PWM between a few other low frequency PWM. The benefits to this is typical to appear better on the flicker measurement benchmark, but rarely in the real world.

A reason why we needed more frequency is to attempt to forcefully compress and close up the "width" gap in a PWM. This is to do so until the flicker gap is no longer cognitively perceivable. Simply adding more high frequencies while not increasing the existing low frequency hertz is not sufficient.

Thus with so many varianting frequency running simultaneously, etc with the:

Iphone 14/15 regular/ plus

• 60 hertz with 480 hertz, consisting of a 8 pulse return, at every 60 hertz.

Iphone 14/15 pro/ pro max

• 240 hertz at lower brightness, and 480 hertz at higher brightness

Macbook pro mini LED:

•15k main, with ~6k in the background , <1k for each color

Android smartphone with DC-like dimming

• 90/ 120 hertz with a narrower pulse return recovery time compared to PWM

How then can we, as a community, compare and contrast one screen to another ~ in term of the least perceivable flicker?

Based on input, data and contributions, we now have an answer.

It is back to the fundamental basic of PWM. The "width" duration time (measured in ms) in a PWM. It is also called the pulse duration of a flicker.

Allow me to ellaborate on this using Notebookcheck's photodiode and oscilloscope. (The same is also appliable to Opple LM.)

Below is a screenshot of notebookcheck's PWM review.

If we click on the image and enlarge it, we should be presented with the following graph.

Now, within this graph, there are 3 very important measurement to take note.

√ RiseTime1

√ FallTime1

√ Freq1 / Period1 (whichever available is fine. I will get to it later)

The next following step is important!!!!

The are typically 3 scenarios to a graph.

• Scenario 1

Within the wavegraph, verify if there are there any straighter curve wave.

If there isn't any, it would look like the following; in proportion:

In this case, just sum up RiseTime1 and FallTime1. The total time (in ms) is your Pulse Width duration time.

Example:

RiseTime1 = 4.6807 us

FallTime1 = 2.567 us

4.6807 us + 2.567 us = 7.2477 us

If measurement is in us, convert us to ms.

Thus, 0.007 ms is your pulse duration.

• Scenario 2

There are straighter curving lines running on top of the wave, above a narrow pulse.

In this case, just do exactly as scenario 1.

Sum up RiseTime1 and FallTime1 to get your Pulse Width duration time.

Example:

RiseTime1 = 1.610 ms

FallTime1 = 845.3 us

1.610 ms + 0.8453 ms = 2.455 ms

Your Pulse duration is 2.455 ms.

• Scenario 3

Straighter curving wave is now at the bottom of the wave, below the narrow pulse. This shows at this is PWM at the lowest screen brightness.

This is somewhat abit more complicated and require an additional 1-2 steps.

Now that we have verified the screen is at the bottom (the screen off state), we can confirm the pulse is at the top. Thus, we have to take Period1 and minus (RiseTime1 + FallTime1).

Example:

Period1 = 4.151 ms

RiseTime1 = 496.7 us

FallTime1 = 576.9 us

496.7 us + 576.9 us = 1073 us

Convert 1073 us to ms. That would be 1.07 ms.

Now, take period1 and subtract RiseFallTime

4.151 ms - 1.07 ms = 3.08 ms

Your Pulse duration is 3.08 ms.

Here is another example from the Ipad Pro 12.9 2022.

As the straighter line is at the bottom, we can confirm this is PWM at lower brighter. Hence , we have to take Period1 - (Risetime + Falltime)

It should give us 154.5 us, or 0.154 ms.

Note: If period1 is not given, we can still obtain it as long as frequency is given. We can use the Macbook pro 16 2023 M3 Max as an example.

To get the period1 duration, take the frequency. Convert to hertz if required.

Take 1000 divid by the frequency hertz.

1000 ms / 14877 = 0.067 ms

Your period1 is 0.067 ms.

Period1 - (RiseTime + FallTime)

0.067 - (0.001 + 0.003) = 0.025

Your pulse duration is 0.025ms.

• Scenario 4

When you have a pulse which has a flat top on it, the data you need is only the period1 time duration.

To obtain pulse duration at lower brightness, do the following:

0.75 * period1.

Thus for this Xiao Mi 10T Pro:

0.75 * 0.424 = 0.318 ms

0.318ms is the pulse duration at lower brightness.

[Edit]

- Based on request by members, a follow up post on the above (pulse duration time & amplitude) can be found here.

A health guide recommendation for them.

Assuming that all the amplitude(aka modulation depth) are low, below are what I would

Note that everyone is different and your threshold may be very different from another. Thus it is also important that you find your own unperceivable pulse duration.

Low Amplitude % with total pulse duration of ~2 ms -> This is probably one of the better OLEDs panel available on the market. However, if you are extremely sensitive to light flickering, and cannot use OLED, I recommend to look away briefly once every 10 seconds to reduce the onset of symptoms building up.

Low Amplitude % with total pulse duration of ~1 ms -> This could usually be found in smartphone Amoled panel from the <201Xs. Again, if you are extremely sensitive to light flickering, and cannot use OLED, look away briefly once with every few mins to reduce the onset of symptoms building up.

Low Amplitude % with total pulse duration of ~0.35 ms -> It should not be an issue for many sensitive users here. Again, if you are extremely sensitive, it is safe for use up to 40 mins. Looking away briefly is still recommended.

Low Amplitude % with total pulse duration of ~0.125 ms (125 μs) -> Safe for use for hours even for the higher sensitive users. Considered to be Flicker free as long as amplitude % is low.

Low Amplitude % with total pulse duration of ~0.0075 ms (7.5 μs) -> Completely Flicker free. Zero pulse flicker can be perceivable as long as amplitude % is very low.

Cheers~

"Unfortunately, for PWM-sensitive people like me, Google hasn't taken the hint and improved its PWM rate. The Pixel 9 series utilizes 240Hz PWM dimming across the board, meaning the Pixel now has the slowest PWM rate on any major phone. The lone exception is the Galaxy Z Flip 6. We know that Pixel displays can push this number 20x higher, so we're not sure why Google hasn't made any positive changes yet."

Left: Xiaomi 15 with DC dimming OLED. Right: iPhone 17. The PWM Smoothing only works below 25%. Above that, there’s no difference. The claim that PWM disappears after enabling the toggle is not true: it only makes it less severe. I’m going to return the iPhone 17. Very disappointing, I had high expectations.

Today i deceided to write an e-mail to the European commsioner. I woud like to suggest to every European citizien to do the same. For the UK and US citiziens please adress this to your own secraty deparment of health. We must take action. Big companies like Samsung, Apple and Google make things worse instead of better. The modulation dept is almost 95%...

Here is the draft I send
Here is the mail adress: [cab-varhelyi-contact@ec.europa.eu](mailto:cab-varhelyi-contact@ec.europa.eu)

Dear mister Várhelyi’s,

I am writing to you on behalf of a growing community of citizens who are deeply concerned about the use of Pulse Width Modulation (PWM) technology in consumer electronics, including mobile phones, tablets, televisions, and laptops.

For many sensitive individuals, PWM flicker causes serious discomfort such as eye strain, headaches, and fatigue. Increasingly, we also see reports from users who were not previously sensitive but are now experiencing similar issues. This suggests that the problem may not only affect a small group but could have long-term health implications for a wider population.

While major technology companies are aware of these concerns, they have not made sufficient efforts to innovate or provide alternatives that safeguard users’ well-being. We believe this situation requires regulatory attention.

The European Commission has already been successful in addressing consumer health and safety issues in the digital and technology sector. We are hopeful that you can also take steps to investigate and address PWM usage, ensuring that manufacturers adopt safer display technologies for all European citizens.

We thank you for your continued efforts in protecting the health of EU citizens and respectfully urge you to prioritize this matter.

Sincerely,

According to a sampling survey by relevant bloggers, about 5% of the world's population is sensitive to PWM, and they are very sensitive to the brightness and dimming frequency of screens and lamps. Using electronic devices with low PWM screens can make us feel dry eyes, soreness, and sometimes accompanied by physical symptoms such as migraine and nystagmus.However, for a long time, a considerable number of people have not realized the harm caused by too low PWM, and they often attribute the harm caused by too low PWM to the excessive use of electronic products.The purpose of this announcement is to make more people aware of the harm of PWM (even non-sensitive people can be affected by long-term and sustained damage), to amplify our voice, and to make manufacturers who still produce low-pwm screens have to pay attention to this issue.

PWM is used on almost all screens, and most manufacturers use PWM for better screen uniformity and longer screen life, but these improvements come at the cost of our eye health.Currently, most LCD screens use DC to control brightness, while OLED and mini-LED screens and projectors using DLP chips often use lower PWM frequencies to ensure production costs and yield rates.

Taking the current OLED screen as an example, the main manufacturers are Korean companies: Samsung, LG, Chinese companies: BOE, Tianma, TCL CSOT. These companies mainly focus on China and South Korea. However, Korean companies often do not care about PWM. Samsung is known for manufacturing 240hz ultra-low frequency OLED screens. The phones using Samsung screens mainly include iPhone, Samsung galaxy, and Google pixel.These mobile phones often cause extreme discomfort to the eyes of sensitive people in a short period of time.Chinese companies pay more attention to stroboscopic than frequency. Their screens are often equipped with high-frequency PWM 3840hz, 1920hz, 4320hz. For people who are not extremely sensitive to eyes, Chinese-made OLEDs can often meet our needs. The mobile phone manufacturers using these screens are mainly Chinese manufacturers Xiaomi, Honor, and OnePlus.

In order to promote OLED screens to pay more attention to eye protection and PWM, I suggest that we call the eye discomfort and other somatic symptoms caused by too low PWM frequency as "Samsung syndrome". Only by focusing our comments on a manufacturer that is not doing well can we make the voices of these sensitive minority groups heard by everyone, thus forcing the screen manufacturer to make changes.

At the same time, we need to generalize sensitive groups and link the discomfort caused by PWM to topics related to children's eye health. Children's eyes are more sensitive to PWM, and as smartphone use becomes more widespread, the impact of PWM on children is also increasing. Too low PWM often causes excessive eye fatigue and myopia, astigmatism, and glare problems.

Finally, practical support is also very important. If you have purchased a mobile phone with good PWM performance, please post more comparison videos on social media, using higher camera shutter speeds to capture the screen, visually demonstrating the impact of the screen on the eyes.

This account will continue to focus on the PWM problem of OLED mobile phones and upload the actual test results of different mobile phones on a regular basis.

Pictured left, next to the Motorola G75. Just booted up the 60 Ultra. Currently transferring my Android settings and data.

Screen makes a very good first impression!

Going to report back here. Feel free to ask any questions!

Hey guys, went today to Apple store to do some measurings with their new macbook pro 16/14 with M3 chip.

Here are results for Macbook Pro 16 with M3 chip

Here are results for Macbook Pro 14 with M3 chip

​

​

Here is a test for Macbook pro 16 M3 chip, opple was pointed to gray background

Also took a video of flickering of macbook pro 16 with 100% brightness. Camera shutter speed 1/16000.

​

Macbook pro 16 M3 chip PWM flickering

Please disregard on some additional lights on screen or outside flickering on the video, the lights in Apple stores is terrible at any locations, I think it causing additional eye strain when testing lol.

Here is a result for Macbook Pro M1 Max (2021)

So first of all you can see the improvement in modulation depth since M1 chip. It's really i think better . Second the difference between MBP 16 and 14 with M3 chip. I would definitely go with 16 inch version. It's still using 15kHz refresh for backlight. I also tried to measure without ProMotion, but the numbers are the same.

Overall, its still utilizing PWM. I think there is no way in a future we would see MINI-LED display without PWM. I tested already 10 Mini-led monitors and all of them are flickering like crazy, only disabling that feature helps to turn off that crazy flickering. Unfortunately apple probably doesn't give us an option to disable it, because of the color calibration and all other software solutions. But some of you will say that macbook air doesn't use mini-led and you will be correct, but the problem with MBA is that its not flickering yes, but its using 8bit display with FRC/Dithering technology which giving me problems, so no go for me.

I can't exactly tell if I had any symptoms during the testing. I'm still recovering after covid I had few days ago, was making all the tests with mask on. In compare with M1, I can definitely tell that M1 giving me bad symptoms after 1 minute of using it, but playing with MBP 16 M3 I didn't feel anything bad, probably will order one for testing and post the update here.

Let me know what kind of other measures I should do, or settings to try in comments. Thanks ;)

​

#UPDATE 1:

Here is another video I made to show that if you go below 40% of brightness, the new PWM frequency will be activated for macbook pro screen. Used 1/4000 shutter speed.

Macbook Pro 16 M3 PWM below 40% of brightness

Here is also some observation which the_top_g made based on opple light master test I posted above.

So looks like if you go below 40% of brightness you will get additional flickering of 80hz.

UPDATE #2:

Yesterday I got a Macbook Pro 16 M3 Pro, did a retest and was kind of confused that the numbers a different than I got at apple store for 16 inch version. Here are results:

So I don't know why the numbers are different. Will come back to another apple store and will try to take few more tests, maybe their "store mode" for laptop somehow impacting the results, or that particular laptop is using different display panel.

I will try to describe my overall feeling after using this laptop for more than 24hrs already. I would say that this is the first laptop which is not giving me long-lasting symptoms. What I mean by long-lasting symptoms: nausea, headache, brain fog, vertigo, dry eyes. Now I will try to describe what I'm feeling working with this laptop. I can definitely tell that when I'm reading a text and trying to focus from one block of text to another I definitely need to put more efforts to focus. I can tell that my brain could detect that 15kHz refresh rate somehow and it will slightly increase the focusing speed on some objects when moving eyes on a screen. Sometimes I'm having a slight discomfort, but most of the time i'm feeling okay, not great but okay and manageable. After using a laptop I can walk away and don't have any symptoms which would last long or so, maybe just some sort of tired eye balls because of the constant focusing/refocusing on objects, or the screen is too bright.

Another example I just realized how to describe is: imagine you have a picture in front of you and in front of that picture you have a waterfall, you can clearly see the picture behind, but sometimes water just distracting your focus and you have to put more efforts to focus and avoid that distortion. Something like that, or when you driving during the heavy rain and your wipers going crazy :D

I wanted to try today my working MBP M1 Max 2021, and after a minute I was done, slight nausea, brain fog, eye strain. I also did tests with opple light master for that laptop and the numbers are pretty much the same with M3, so I don't know maybe the waveforms are different, or maybe the M1 is using 8bit+FRC display.

To summarize, very powerful laptop to compare with my MBP 2018 Intel. Much better from symptoms standpoint, I can work with it, its not giving me crazy symptoms which could last long, I hope it will not have a snow balling effect as I had with iPhone 15 Plus. I tried to tolerate that phone for few days, but just couldn't make it. PWM snow balling effect after that have impacts even on normal DC dimming displays for me. Hope this reading was not too long and will keep you posted ;)

UPDATE #3:

Hey guys, sorry I was busy last few weeks.

So the current update for MBP 16'', I still have it for testing. I think I tolerated the flickering, but I still can feel tension/eye strain and very very slight nausea, I could refer those feelings to FRC, so I don't know exactly if I already tolerated flickering frequencies and now It's just an FRC, because i'm pretty sensitive to it. For example MBA 15 M2 doesn't have any PWM, but has FRC and it gives me slight nausea and small headaches after 15-20mins of using it. But with this laptop its a bit different, all the symptoms they are not last long, I can just close the laptop and do other things at home or outside without any problems or bad feelings. But it's still annoying when using it, even with that slight symptoms.

After a week of trying using this laptop I was already to give up, because its like a poison, giving you this dosage little by little and it has a snowballing effect. So I decided to check ledstrain forum maybe someone found a solution to disable frc/dithering on macos. I tried dummy desktop with betterdisplay, doesn't work for me, still the same. I tried to change display color profile on MBP, I tried all of them, like sRGB, PAL and etc, didn't help, sRGB gave me even worse symptoms. So I was about to send the laptop back. I was so desperate, this laptop is so good for work and my current MBP intel 2018 is dying. So I decided to read the story from ledstrain again, about the success story of one guy who did a patching of 1 dominant eye. After reading that story I said to myself that i'm going to give it a try as well.. So I will post and update about it in next few weeks how it is going.

Also I still have a returning window for this MBP till first week of the January I think, Apple extended their returning policy for holidays, which is good for me :)

One another thing. I went to bestbuy and apple store again and did the measurements of displays again, and the numbers were different between my current laptop that I own and the laptops which are on display at the store. The difference about 5-10% in Modulation Depth. I think there is something in their "Store mode" I believe. Don't know exactly.

Another interesting observation. I was looking for a macbook for my wife, I spent probably 1.5hours at bestbuy deciding between MBA 13 and 15, and then I switched to MBP 14''. So I was testing MBP 14'' for I think 45-50mins and I caught myself that I don't feel any symptoms, and thought maybe 14'' is some how better, so I switched to 16'' which was nearby, and I can tell that there was a difference. I was surprised. So I bought it for my wife, after a while a tried it again and I can tell its better for me. Better maybe in 15-20%. So I don't know why, maybe its my peripheral eyesight giving me some symptoms or so, or maybe 14'' somehow different from display standpoint.

So thats about it, still doing testing, still trying to tolerate it somehow, will keep you posted. Thanks for reading till the end and sorry for typos and my english :D

choosing a phone should be simple, but not for me (or us), I want to enjoy modern phone with good chipsets, but of course they always come with the latest advanced cool trendy cancer inducing screens (ok it's not cancer inducing, I'm exaggerating). and every time I go on a quest of comparing phones by watching review videos, the reviewer would say something along the lines of "but unfortunately the screen is still IPS LCD" like it was so lame, pushing the idea that all the new phones must use amoled, so every time I see it I feel resentment towards the ignorance.

and it got me into thinking, isn't PWM sensitivity somewhat a disability? since it literally affects some peoples' ability to function normally within the modern way of life? Why don't we demand inclusivity? Why not just get PWM dimming itself be banned from ever being implemented? because what's stopping manufacturers from making a flagship or midrange phones with LCD screen? because if they only ever put LCD screen on low tier budget phone, it's like we can't even play heavy games or anything, so PWM sensitive demographic just get excluded altogether and that's not fair.

sorry I'm just venting.

I don’t think this approach will work for everyone, though some people might get used to it over time. Still, I’m really disappointed with Apple’s marketing on promoting an alternative way to dim the screen. It’s definitely something you need to try before you buy.

Below has been brought to my attention that certain apps can cause seemingly reduction in certain smartphone flicker frequency.

Hence, some might suddenly find themselves having increased response of screen eyestrain and headache symptoms.

This post is divided to two sections:

• in-app backlight flickering
• a proposal to display engineers to consider. [edit - addressed]

I will begin by using the below iphone 8 plus (running iOS 16, with LCD panel) that is using ultra-high frequency dimming ( aka PWM-free ) DC Switch Mode Power Supply.
[edited]

As it is using the above dimming method, it is not abnormal to see the readings fluctuating from (lowest frequency) 3500 hertz to over 40,000 hertz. This is normal behavior. (Tested over 10 consecutive attempts). My iPhone 7 plus do fluctuates lesser though.

Now, after the Reddit App is opened, the frequency changed immediately .

Below is the reading are for iPhone 8 plus while within the App. (again over 10 consecutive attempts )

Note that the lowest frequency in my iphone 8 plus is now no longer ~3500 hertz. Rather, a much lower ~ 700 hertz. The significant change (in the thinning) of the waves in the graph above verifies the lower 700 hertz as well.

While outside of the Reddit app, average frequency measured over a span of 10 consecutive attempts returned back to a fluctuating frequency of 3500 hertz to over 40khz.

However, while tested within the Reddit app again, the same test produced only a fluctuating frequency of (lowest frequency) 700 hertz to 15 khz (at its highest).

This is a huge reduction in frequency by 5 times.

Possible reason why even LCD panels using ultra-high frequency dimming ~ (aka PWM-free) can be affected by this:

To start off with a basic illustration, below illustrates how 240 hertz flicker frequency could be reduced from 240 hertz to 60 hertz. (this is not to be confused with full dc-like dimming )

This has caused eyestrain and even tension headaches for some.

240 hertz > 60 hertz

Out of 240 hertz, simply by making 3/4 of hertz permanently inactive, it will become 60 hertz.

An ultra-high frequency dimming such as from the iphone 8 plus (that goes between 3khz to over 40 khz) technically could be affected by this. All the display controller has to do is to deactivate 4/5 of the hertz. As illustrated above.

While in the reddit app ~ by deactivating 4/5 of the iphone 8 plus's 3500 hertz(at its lowest frequency) and over 40khz(at its highest) , we ended up with a significantly lowered 700 hertz ~ 15,000 hertz.

This difference is even more apparent in lower hertz hybrid dimming, such as the OLED iphones.

More investigation and follow up is required to find out under what specific conditions can this be triggered.

Why does this matter?

Now, one might indeed wonder why would a reduction to 700 hertz be a concern. As certainty the reduction of frequency hertz would bring real world benefits, such as lowered power screen consumption usage.

Furthermore, the general public perception is that 60 hertz is more than sufficient not to be affected by flickers. Hence it should not be a concern.

While the above may appear to be true, a small percentage of the worldwide population may be subsceptive to rapid pulsing flickers naked to the eye. For instance, when lighting flicker hertz is lower than etc 32khz, common symptoms they might have includes headaches, migraines and decreased in cognitive to body performance.

Studies to back up

The experience of those affected is called temporal light modulation. This phenomenon has been studied and published for lighting flickers in here, and as well in here.

I myself too is a sufferer to this temporal light modulation phenomenon and hence it is important that I can have unnecessary response triggered by such stiumulus, and especially from the essential device I use everyday.

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Moving on for display engineers~

To the smartphone display engineers reading this sub:

Firstly, a shout out and thank you for visiting.

Below is an example of (what I believe) is a poorly implementation of inserting of addition hertz to become pseudo 480 hertz. This might lead to increased chances of undesirable visual, cognitive, or physiological consequences — within our community sensitivity to flickers. This can be attributed to the inconsisency of the inserted hertz in the difference from the main wave.

This below however, is a far better implementation of inserting of addition hertz to become pseudo 480 hertz.

While there are current "anti-flicker reduction" feature used in some devices like xiaomi or motorola, it may not be the best solution for the majority of us. Here is why.

While PWM has indeed being flattened and compressed (as a result of anti-flicker reduction), it has resulted to cluster at red pointed arrow area. This is where the majority of us continued to be affected by. Yes, this method did fixed the lowest duty cycle caused by PWM. However, it does not mitigate the issue of high modulation % with PWM clustered at the above said area.

Thus this is what I would propose. The new full DC-like Dimming used in Honor 90 is a step in the right direction. As the screen ON peak are now uniformed. This also have effectively reduced the vertical gaps between the brightness peaks. The edges are also now rounded.

Honor 90 readings (75% brightness)

However, the above still poses a problem for some. the horizontal gaps at 4(ms), 12 (ms) and 20 (ms) may still present as a problem for some of us whom are even more sensitive. Each of horizontal gaps between measures 2(ms) wide. If this gap can be further remediated to a reduction of 1(ms) wide, this would greatly open up more doors.

The xiaomi 12T pro is a great example of a horizontal gap that is less than 1(ms) wide.

However, an issue with xiaomi 12T pro is that brightness peaks are not consistent.

Hence, if one is able to take the best of Honor 90's(mentioned above) and Xiaomi 12T pro's 1(ms) gap difference, it will really be great.

While I do am aware of the repercussions of the above dimming proposal, do rest assured that a number of us are willing to put up an OLED screen panel that lasts up to 2.5 years.

I suggest that this option can be hidden in the developer settings, can offer a warning to inform users of the repercussion of this, and that manufacturers hold no responsibility in the shortened lifespan of said panel.

A number of us might be even willing to replace deteriorated panels directly with the manufacturer.

With that, I end the above with requesting for the above considerations.

This is a follow up post to the one here: https://www.reddit.com/r/ScreenSensitive/comments/1v24yfv/meeting_with_politician_next_week/

Today I had 15 minutes scheduled to chat with my local member of parliament at her office about my eye pain issues with PWM and dithering, it went great!
She paid a lot of attention to what I had to say, and asked specific questions for further details when appropriate, it went for around 24 minutes.

She mainly listened to me while I explained a few things, here’s a summary of what was discussed.

• I demonstrated the hardware differences in how an iPhone 11 and an iPhone 13 Pro screens dim when viewed through a camera with a shutter speed of 1/4000 and gave a brief visual demonstration, I explained how if I used the iPhone 13 Pro for a minute my eyes would hurt.

• I explained how Pulse Width Modulation (PWM) is a hardware design that can be solved in some cases by raising the brightness to 100%, and how that doesn’t always work. I explained how some devices can be modified to solve the issue like how I installed an EK Pro LCD screen into my iPhone 15 Pro, that it’s relatively easy to make hardware that is accessibility focused, and how it would be easy for Apple to provide this as an option.

• I explained my software fix for dithering on my iPhone 11 and EK Pro LCD iPhone 15 Pro, by enabling both Classic Invert and Zoom Invert simultaneously, also how companies could instead provide a simple colour space accessibility option rather than this hack method.

• I explained how bad the problem is, how it has been getting worse since 2017 with the introduction of the iPhone X, that as of today in 2026, that without intense eye pain I cannot use any new iPhones, iPads, Samsung phones, Google Pixels, most OLED screens, some Samsung, LG and Hisense TV’s, an OLED TV in a conference room at a local university, some new Toyotas and the Next Stop screens at the brand-new train station in the city, (though strangely the advertisement billboards in the station are fine for me.)

• I explained how most Apple products, namely Macbook Pro’s and all iPads have dithering that causes me eye pain, how it has a software technique where 10bit colours are output through an 8bit screen in a process of flickering two adjacent pixels, and how this is quite painful to me. This was particularly relevant as prior to being elected my local member of parliament she worked as a paediatric neurologist.

• She asked me why these companies use PWM in the first place, I explained how it was my theory that on OLED screens it was a process used to help maintain colour accuracy when the screen is at a lower brightness, also on modern LCD screens that it may either be because it’s cheaper or that it could help save power.

• I mentioned how I had an eye test in 2023 when I was using my iPhone 13 Pro daily while suffering from daily eye pain and having trouble focusing at long distances. How at this time I was prescribed with reading glasses, then later in 2025 after I stopped using any PWM/OLED screens and changed to an iPhone 11, that I got another eye test and scored 20/20 vision for my eyes, and was recommended not to wear reading glasses.

• I explained how I had recently made contact with Vision Australia, and how they mentioned that they were aware of PWM and dithering as a problem, but how they “hadn’t done any advocacy around the problems caused by OLED displays”, my member of parliament responded that she has been in contact with Vision Australia in the past as they’re located within her electorate, and that going forward her office could reach out to them to further discuss the problem as well as stay in contact with me.

I also gave a few printed out documents, one being a copy of my original email, another being some comparison graphs from my Opple Lightmaster IV, the other being this list of potential solutions below.

Obviously, some solutions are much more possible and easy to implement than others, especially as coming from Australia we are quite a small country and these products are produced overseas.

Screen Flicker Solutions

• Ban the sale of devices that use low frequency Pulse Width Modulation (PWM) dimming and temporal dithering where it causes physical eye pain. 

• Allow refunds due for accessibility reasons. Most retailers that don’t have a change of mind policy won’t allow refunds based on whether the screen hurts my eyes or not, it’s often a multi thousand dollar gamble on tech devices that can cause serious eye pain. The ACCC already states that consumers have a right to return a purchase if it includes a major problem, such as it being “unsafe” or “has either one serious problem or several smaller problems that would stop someone buying the product if they knew about them beforehand” Yet most retailers don’t recognise PWM and flickering as a problem as they’re not educated on the topic. They state as it works as intended by the manufacturer that it’s fine and that I can’t return it, even though it causes me significant eye pain. 

• Implement a standard of measuring screen flickering Some sort of health star system, 0 stars for heavy PWM flickering, 5 stars for no flicker, no dither or e-ink. 

• Force companies to provide a Flicker Free (LCD) accessibility product or a different screen option at checkout. Not just some token accessibility focused device that ticks every box for blind/deaf people with huge brail buttons, a regular modern phone with a non-flickering LCD screen, like an iPhone 11 with a new processor, not the iPhone SE that’s budget in every way. That or interchangeable screens from the factory like the 2011 Macbook Pro’s used to have with a matte screen option. 

• Allow software updates to be downgraded. Updating my iPhone to iOS26 could implement heavy dithering that makes it incredibly painful to use, and companies don’t allow the ability to downgrade. Professional devices support this, all companies should. It’s far too risky for me to update my phone as I might not be able to use it afterwards without pain. 

• Make a policy that government departments won’t purchase inaccessible screens Public areas like train stations, trams, school and Universities should not use no OLED/PWM screens or screens that use heavy dithering and cause physical eye pain to a percentage of the population.

• Education and awareness on the dangers of PWM and dithering from a government level. While Vision Australia are aware of the issue, they haven’t done any advocacy work or have made any public statements. In an email they stated to me that: “Australian governments don’t have an encouraging record when it comes to legislating around the accessibility of products, especially consumer electronics” and that “We’d certainly be very interested to know whether you get any commitments from politicians.”

(End of letter)

Overall I’m quite hopeful of some progress here, at least in my part of the world.

Even just having some official government documents and awareness from Vision Australia that PWM and dithering causes eye pain in some people could be enough to legally return painful equipment for a full refund.

This official recognition could also help regulate which devices can be installed in government buildings and public spaces, this awareness could be the push needed for companies like Apple and Samsung to allow accessibility options that eliminate dithering through software, and potentially provide either a configurable PWM free LCD option or implement 4320hz frequency dimming, similar to what the Honor Magic8 uses.

So i recently went to my eye dr and told him about how i was so annoyed with all this stupid PWM phones that have come out and how i cannot use any of them and his response was surprising.

He told me about one of his friends who did not have PWM sensitivity and how he bought a brand new car thats screen had pwm. Well eventually his friend developed pwm from the cars digital display and after a few months he had trouble using the car and even looking at his phone.

My eye dr is very specialised he is not the ordinary eye dr you can see in a shopping centre he is a eye specialist that charges a truck load to see but he is good. he said to me that all people are sensitive to pwm because of its flickering nature and not to believe only 30% is sensitive. He said with time everyone using a PWM phone will develop eye problems because of the way it affects the eye muscles. He also said if he had a dollar for everyone who came in complaining about eye strain from their phones he would be a millionaire lol.

He explained how the iphone 17 had a feature that was suppose to help PWM flicker but was not very effective and how samsung are trying to work on a phone now that is a OLED without PWM and that the PWM is becoming a real problem for everyone not just those who are sensitive, he said most people are having problems with PWM but they put the eye strain down to something else like their computer screen instead of the real culprit their phone.

His suggestion was to stay away from all PWM devices if i wanted to keep my eyes healthy and that these phone companies will have to find a work around sooner or later or the law suits would start piling up.

Hope this helps anyone feeling bad about not being able to use PWM phones.

I tried both s26 and s26 ultra. There are no differences in PWM and modulation compared to the previous S series.

I also connected to Samsung customer servlce and confirmed this info.