Other Why some of us are worried about an all OLED iPhone lineup.

Stuey3D

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So you may have come across the 3 letters PWM among these various forums when people discuss the OLED iPhones and the rumour that the 12 series will all be OLED based.
Some of you wonder why some of us make a big deal of it because you can’t see it or it doesn’t effect you, well I have a video I recorded of my laptop which shows PWM in action in quite a dramatic fashion which hopefully might visually show why some of us are really worried about an all OLED iPhone lineup.

So what is PWM? PWM stands for Pulse Width Modulation and is used in various applications for reducing the brightness of lights or slowing down motors etc, it is a Pulse of electricity rather than a constant source of electricity and Pulsing lights at high frequencies has the effect of making them appear dimmer to the naked eye due to how our sight works. PWM is an all digital solution and cheaper/smaller to implement the controllers vs an analogue controller which would lower the voltage/current.

Some of us are sensitive to PWM in lighting applications and it can cause eye strain and headaches sometimes these can be quite severe. This is because when you dim a screen you are generally in a dim environment and your pupils are dilated to let in maximum light and the screen of the device you are using is pulsing at full brightness directly into your dilated pupils causing eye strain and headaches. Most people won’t suffer from this and those of us who do don’t realise it is happening because the pulsing is happening fast enough for us not to see the flicker with our naked eyes.

PWM itself is not actually the issue for most of us, what is the issue is the frequency of the PWM the lower the frequency the more pronounced the flicker and that is what causes the headaches. For me personally when PWM gets to around the 200hz mark that is when I get headaches, yet my TV which is a Sony Full Array local dimming set uses a PWM frequency of 720Hz which isn’t an issue for me unless I activate the black frame insertion mode which lowers the PWM to 120Hz.

So why is it a problem on iPhones then? Well iPhone OLED’s pulse at 240Hz which is where most of us will feel the eye strain. I had an iPhone X for a year and got these headaches that couldn’t be explained I went to the opticians the doctors etc but they couldn’t figure out why, it was only when I stumbled across a post on this forum where I realised that was the issue. When I traded my X for an XR the headaches went away.

Well the last couple of weeks the headaches came back, turns out the LCD in my cheap little ExBusiness laptop I recent got uses PWM at 220Hz a very similar frequency to the iPhone. As it was an LCD I never thought it would use a PWM frequency that low so it never occurred to me that it was causing my headaches until I recorded this video...



The Lenovo X230 with PWM is to the left and my 2012 MacBook Pro is to the right, see how dramatic the PWM is with the flicker and black strobing bar on the screen. This is the cause of our pain. I would love to know how this would effect people with epilepsy as if it’s enough to cause us eye strain and headaches god knows what someone with epilepsy would be going through.

PWM is needed in small OLED screens because you cannot simply lower the voltage to dim the screen as it causes the colour to shift and go all wonky, so this is why a lot of us are concerned about an all OLED iPhone lineup going forward because we will no longer have an upgrade path. What is also concerning is everything bar the cheapest Android phones or the iPhone SE (which for us with an iPhone XR or 11 would be a downgrade) all use an OLED screen. This is why you see PWM mentioned a lot in these forums.

Hopefully this video will show what you can’t see and hopefully it will show you why some of us really struggle with certain screens.
 

snipr125

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Oct 17, 2015
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UK
I am genuinely concerned about pwm on oled screens. Up until now the only oled phone i have owned extensively has been a samsung galaxy s3 back in 2012. All my phones since then have used lcd ips displays which have not triggered migraines. I do however sometimes get blurry vision (scotoma), which lasts about 20 mins and then goes away. It can be quite intense, and problematic when at work. I have narrowed the cause to dehydration, but i am worried that pwm may trigger it also (i intend to get the 5.4 iphone 12, which has oled).
 

Stuey3D

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I am genuinely concerned about pwm on oled screens. Up until now the only oled phone i have owned extensively has been a samsung galaxy s3 back in 2012. All my phones since then have used lcd ips displays which have not triggered migraines. I do however sometimes get blurry vision (scotoma), which lasts about 20 mins and then goes away. It can be quite intense, and problematic when at work. I have narrowed the cause to dehydration, but i am worried that pwm may trigger it also (i intend to get the 5.4 iphone 12, which has oled).
PWM certainly wont help any vision issues. I am personally hoping micro led hurries up becomes ready for mainstream devices as that is the gold standard so far. Its OLED without the drawbacks.
 

Moonjumper

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Jun 20, 2009
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PWM certainly wont help any vision issues. I am personally hoping micro led hurries up becomes ready for mainstream devices as that is the gold standard so far. Its OLED without the drawbacks.
microLED is looking likely to have PWM, just as both OLED and LED (still a misleading name, it is just LCD with an LED backlight) do. Note that there are both OLED and LED with and without PWM, and hopefully it will be at least the same for microLED, and preferably as performant and rare as it is heading towards with LED.
 
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Stuey3D

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microLED is looking likely to have PWM, just as both OLED and LED (still a misleading name, it is just LCD with an LED backlight) do. Note that there are both OLED and LED with and without PWM, and hopefully it will be at least the same for microLED, and preferably as performant and rare as it is heading towards with LED.
It’s not the PWM itself that’s the issue for me it’s the PWM frequency being too low that’s the issue. If they had an OLED or Micro LED with a PWM rate of near to 1000Hz than for me my headaches go, as I’ve said above my Sony TV has a PWM rate of 720Hz and that is a non issue for me.

What I really hope that Apple does is put an accessibility setting in to reduce PWM flicker like the OnePlus phones are trying to do with their DC Dimming setting. Put it in accessibility and put the caption reduces screen flicker that can cause eye strain and headaches, this setting may effect colour accuracy at lower brightness levels.

Doing that Apple fixes the PWM issue for us who suffer, yet can still use the OLEDs that people want.
 

one more

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Aug 6, 2015
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Is this also an issue on high-end Samsung phones? I have not used an OLED screen myself, but asked a few of my Android-using friends with Samsung and Huawey phones and none of them had any complaints.

Curiously enough, when I switched from iPhone 7 to iPhone 11 I started getting really sore eyes too, even though iPhone 11 is still using an LCD screen. What fixed it for me was reducing the White Point and disabling Face ID “awareness” features.
 
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Moonjumper

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It’s not the PWM itself that’s the issue for me it’s the PWM frequency being too low that’s the issue. If they had an OLED or Micro LED with a PWM rate of near to 1000Hz than for me my headaches go, as I’ve said above my Sony TV has a PWM rate of 720Hz and that is a non issue for me.

What I really hope that Apple does is put an accessibility setting in to reduce PWM flicker like the OnePlus phones are trying to do with their DC Dimming setting. Put it in accessibility and put the caption reduces screen flicker that can cause eye strain and headaches, this setting may effect colour accuracy at lower brightness levels.

Doing that Apple fixes the PWM issue for us who suffer, yet can still use the OLEDs that people want.
Yes, the frequency is a large part of how many people it affects, and I hope the screens are much better on the next generation of iPhones. The only OLED screen I use regularly is a Panasonic TV, which uses an LG panel, and has no PWM. I used to have an LCD monitor that did give me headaches caused by PWM, so I am aware of how bad it can feel. The OLED iPhones is the first time many have encountered the issue, and think it is an OLED problem, but occurs across many screen technologies. I think the iPhone OLED screens might have it worse because they also have Samsung's PenTile technology (which shares sub-pixels across pixels) that can cause visual artefacts.

I was pointing out microLED might not be the solution, although I hope it is. Electroluminescent Quantum Dots (self-emitting, unlike the current photoluminescent QDs) is the other screen technology that I hope makes it to market, but I cannot find any information about the potential for PWM with that.
 

Northern Man

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Aug 25, 2013
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So you may have come across the 3 letters PWM among these various forums when people discuss the OLED iPhones and the rumour that the 12 series will all be OLED based.
Some of you wonder why some of us make a big deal of it because you can’t see it or it doesn’t effect you, well I have a video I recorded of my laptop which shows PWM in action in quite a dramatic fashion which hopefully might visually show why some of us are really worried about an all OLED iPhone lineup.

So what is PWM? PWM stands for Pulse Width Modulation and is used in various applications for reducing the brightness of lights or slowing down motors etc, it is a Pulse of electricity rather than a constant source of electricity and Pulsing lights at high frequencies has the effect of making them appear dimmer to the naked eye due to how our sight works. PWM is an all digital solution and cheaper/smaller to implement the controllers vs an analogue controller which would lower the voltage/current.

Some of us are sensitive to PWM in lighting applications and it can cause eye strain and headaches sometimes these can be quite severe. This is because when you dim a screen you are generally in a dim environment and your pupils are dilated to let in maximum light and the screen of the device you are using is pulsing at full brightness directly into your dilated pupils causing eye strain and headaches. Most people won’t suffer from this and those of us who do don’t realise it is happening because the pulsing is happening fast enough for us not to see the flicker with our naked eyes.

PWM itself is not actually the issue for most of us, what is the issue is the frequency of the PWM the lower the frequency the more pronounced the flicker and that is what causes the headaches. For me personally when PWM gets to around the 200hz mark that is when I get headaches, yet my TV which is a Sony Full Array local dimming set uses a PWM frequency of 720Hz which isn’t an issue for me unless I activate the black frame insertion mode which lowers the PWM to 120Hz.

So why is it a problem on iPhones then? Well iPhone OLED’s pulse at 240Hz which is where most of us will feel the eye strain. I had an iPhone X for a year and got these headaches that couldn’t be explained I went to the opticians the doctors etc but they couldn’t figure out why, it was only when I stumbled across a post on this forum where I realised that was the issue. When I traded my X for an XR the headaches went away.

Well the last couple of weeks the headaches came back, turns out the LCD in my cheap little ExBusiness laptop I recent got uses PWM at 220Hz a very similar frequency to the iPhone. As it was an LCD I never thought it would use a PWM frequency that low so it never occurred to me that it was causing my headaches until I recorded this video...

View attachment 929586

The Lenovo X230 with PWM is to the left and my 2012 MacBook Pro is to the right, see how dramatic the PWM is with the flicker and black strobing bar on the screen. This is the cause of our pain. I would love to know how this would effect people with epilepsy as if it’s enough to cause us eye strain and headaches god knows what someone with epilepsy would be going through.

PWM is needed in small OLED screens because you cannot simply lower the voltage to dim the screen as it causes the colour to shift and go all wonky, so this is why a lot of us are concerned about an all OLED iPhone lineup going forward because we will no longer have an upgrade path. What is also concerning is everything bar the cheapest Android phones or the iPhone SE (which for us with an iPhone XR or 11 would be a downgrade) all use an OLED screen. This is why you see PWM mentioned a lot in these forums.

Hopefully this video will show what you can’t see and hopefully it will show you why some of us really struggle with certain screens.
Excellent post. I tried the new iPhone SE and had to get rid of it due to eye strain and headaches. But no problems with the original SE or my Samsung Galaxy S10e (which is Amoled or Oled). So as you say, it can occur on LCD as well.
 

Stuey3D

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What I am finding hard to believe is that a large company like Apple who prides themselves on accessibility appears to be ignoring this issue. We are but a few informed people on a forum, how many other people are out there getting unexplained headaches not realising it’s their phone causing them? As the issue is constantly brought up when ever OLED is mentioned I am betting quite a large subset of population is effected by this to some degree, right now Apple can advise people to buy the iPhone 11 if they want the latest device with less chance of PWM headaches, but when the 12 series comes out and the older models slowly leave the product line Apple are stuck with a bunch of phones a lot of people cannot use safely.
 

DevinNj

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Apr 27, 2016
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What I am finding hard to believe is that a large company like Apple who prides themselves on accessibility appears to be ignoring this issue. We are but a few informed people on a forum, how many other people are out there getting unexplained headaches not realising it’s their phone causing them? As the issue is constantly brought up when ever OLED is mentioned I am betting quite a large subset of population is effected by this to some degree, right now Apple can advise people to buy the iPhone 11 if they want the latest device with less chance of PWM headaches, but when the 12 series comes out and the older models slowly leave the product line Apple are stuck with a bunch of phones a lot of people cannot use safely.
You have a great point here, I feel for the general crowd, those not in the know, that may be experiencing headaches. Imagine what they go through trying to diagnose why the headaches are happening. I can only imagine that's very stressful and maybe even leading to misdiagnoses, causing even more unwanted/unneeded aggravation.
 
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snipr125

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Oct 17, 2015
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Excellent post. I tried the new iPhone SE and had to get rid of it due to eye strain and headaches. But no problems with the original SE or my Samsung Galaxy S10e (which is Amoled or Oled). So as you say, it can occur on LCD as well.
im really sorry that you got headaches and eye strain with the 2020 SE. Just curious, have you also used the iphone 7 or 8, as they have the exact same screen as the SE (true tone and p3 colour gamut). The original SE, 6, 6s, 5s do not have true tone or p3, so may this is what gives you eye strain?
 

Stuey3D

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You have a great point here, I feel for the general crowd, those not in the know, that may be experiencing headaches. Imagine what they go through trying to diagnose why the headaches are happening. I can only imagine that's very stressful and maybe even leading to misdiagnoses, causing even more unwanted/unneeded aggravation.
I did go through that, I went to the opticians and doctors and they couldn't figure it out. Optician said I was very slightly short sighted but could live without glasses.
 
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DevinNj

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I did go through that, I went to the opticians and doctors and they couldn't figure it out. Optician said I was very slightly short sighted but could live without glasses.
Oh man sorry to hear, that's horrible. Just horrible. I really hope this is something that new technology can mitigate.
 

Northern Man

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Aug 25, 2013
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im really sorry that you got headaches and eye strain with the 2020 SE. Just curious, have you also used the iphone 7 or 8, as they have the exact same screen as the SE (true tone and p3 colour gamut). The original SE, 6, 6s, 5s do not have true tone or p3, so may this is what gives you eye strain?
You may have a point. I never had the 7 or 8.
 

Stuey3D

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Oh man sorry to hear, that's horrible. Just horrible. I really hope this is something that new technology can mitigate.
Thankfully wasn't that bad for me as I just lived with the headaches dismissing them as other things being such as being tired/dehydrated etc I never went to the doctors just the opticians. I can imagine some people who might have pushed further than me might have been subjected to all sorts of scans and stuff trying to figure out the headaches, which in a country like the USA is likely to bankrupt them.
 

freeagent

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Mar 9, 2020
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I recorded a slowmo of my kid knocking down a block tower in a room lit by an led bulb. I didn’t see anything but when we watched the video it flickered the same way those laptops were. It wasn’t my screen flickering but the light flickers so fast you can’t see it until you slow it down. PWM is everywhere. TVs, computers, fans, etc.
 
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Stuey3D

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I recorded a slowmo of my kid knocking down a block tower in a room lit by an led bulb. I didn’t see anything but when we watched the video it flickered the same way those laptops were. It wasn’t my screen flickering but the light flickers so fast you can’t see it until you slow it down. PWM is everywhere. TVs, computers, fans, etc.
I know PWM is the cheap way to dim lights and slow motors. I guess the reason people don’t get headaches with room lights is due to the fact you aren’t staring directly at them, and the fact that they are lighting an entire room means your pupils are more constricted due to more light surrounding you. Screens are an issue because they are a single small bright spot in what would be a dim environment so your pupils are dilated to let more light in due to the lack of ambient light around.
 

Moonjumper

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I know PWM is the cheap way to dim lights and slow motors. I guess the reason people don’t get headaches with room lights is due to the fact you aren’t staring directly at them, and the fact that they are lighting an entire room means your pupils are more constricted due to more light surrounding you. Screens are an issue because they are a single small bright spot in what would be a dim environment so your pupils are dilated to let more light in due to the lack of ambient light around.
As you say, it is the cheap way, which seems wrong on a premium device like the iPhone. It is particularly bad with them having a low frequency. Preferably it should be above 500 Hz to avoid any stroboscopic effects, whereas they are apparently 240.
- - Post merged: - -

Excellent post. I tried the new iPhone SE and had to get rid of it due to eye strain and headaches. But no problems with the original SE or my Samsung Galaxy S10e (which is Amoled or Oled). So as you say, it can occur on LCD as well.
Apparently the new SE doesn't have PWM. This is a good site for finding out about which screens have it: https://www.notebookcheck.net/PWM-Ranking-Notebooks-Smartphones-and-Tablets-with-PWM.163979.0.html
 
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wmdunn

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Dec 13, 2012
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So last year when I went from my 2016 SE to the iPhone X, I immediately began having headaches and eye strain. Had no idea about oled screens or pwm. Since I had no issues with iPhone lcd screens (SE, 8, 7), I purchased a XR ... immediately had more headaches, eye strain, even though it has an lcd screen.

Decided to try the Samsung Galaxy S10e, which has an oled screen ... no issues at all. My unprofessional hunch is that there is something about Apple's face ID, that is the culprit.
 
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Stuey3D

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So last year when I went from my 2016 SE to the iPhone X, I immediately began having headaches and eye strain. Had no idea about oled screens or pwm. Since I had no issues with iPhone lcd screens (SE, 8, 7), I purchased a XR ... immediately had more headaches, eye strain, even though it has an lcd screen.

Decided to try the Samsung Galaxy S10e, which has an oled screen ... no issues at all. My unprofessional hunch is that there is something about Apple's face ID, that is the culprit.
Maybe the FaceID is the culprit for some people, but for me personally its the screen. When I went from the OLED X to the LCD XR the headaches went away for me. They first came back when I first got my Apple Watch Series 3 and spent ages looking at it during setup which confirmed to me the OLED was the issue, and now with the PWM in my Lenovo I am getting them again due to the similar frequency PWM it uses.
 

wmdunn

macrumors member
Dec 13, 2012
46
26
Phoenix, AZ
Interesting ... my headaches continued even when I went from the X to the XR. And now, no headache or eyestrain in the 6 months that I've had the S10e, which is oled. Really hope that Apple addresses the issue, as I'm very interested in the new 5.4 iPhone 12.
 

Stuey3D

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Interesting ... my headaches continued even when I went from the X to the XR. And now, no headache or eyestrain in the 6 months that I've had the S10e, which is oled. Really hope that Apple addresses the issue, as I'm very interested in the new 5.4 iPhone 12.
You are the 2nd person to comment that the S10E doesn’t cause headaches but I find that odd as it uses a PWM frequency of 232Hz which is down there with the iPhone and the Lenovo laptop of mine. Curious how things effect people differently ‘eh I’m pretty sure if I used an S10E it would be torture for me headaches galore.
 
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