PWM Screen Flickering Symptoms — 10 Tips: Headache and Eye Strain

This is one of my most important posts, and it concerns health. It covers my personal experience of 2.5 years with PWM and Device Screens, and it cannot be applied specifically to you.

1. PMW (Pulse-width modulation) is Screen Flickering and the Human Brain and Eyes can’t process it correctly, that causes headache, eye strain and other unpleasant symptoms.
   
   I first encountered a PWM problem in early 2022 when I bought a MacBook Pro M1 Max 16″ that was refunded after a week due to symptoms.
2. Six months later, I felt that it was difficult to stay in modern shopping malls for a long time because they were trying to install LED Lighting to save electricity everywhere.
   
   Cheap LED Lamp can cause the same symptoms.
3. I was absolutely happy with my iPhone XS Max for 5 years, and it was enough for my Game Development purposes.
   
   In 2024, I switched to the iPhone 15, and here are the symptoms. I can’t refund it because there are no alternatives from Apple to work.
   
   But fortunately, I rarely use it during the day because I spend my main working time behind the screen of the MacBook Air 13 M2 2022, which has no Flickering.
   
   PWM checking you can get with the next website before buying any equipment.
4. Even if you don’t have any symptoms, it doesn’t mean that your body won’t respond later. There is Subreddit called PWM_Sensitive to discover more information.
   
   The sensitivity of each person is different and may also depend on the PWM Frequency. This explains why I haven’t had symptoms with the iPhone XS Max, which has PWM.
5. If this is an IPS screen, then likely it will have no PWM.
   
   So the latest iPhone with IPS Screen without PWM is iPhone 11, which can still be bought in unpacked state.
   
   Android phones and Windows computers provides more flexibility in choosing a device, and you can buy a modern device without PWM. Manufacturers are aware of this problem and often write words like “Flicker Free” on promotional materials.
6. Even regular Non-LED Lamps in some apartments can cause the mentioned symptoms. I guess it depends on the Current that comes into your apartment or on the features of the main electrical panel. I didn’t figure it out, so I would appreciate any hints on this issue.
   
   This effect was revealed by testing identical regular Non-LED light bulbs in different apartments.
   
   Expensive LED light bulbs contain a kind of “stabilizers” that can remove symptoms even in a “bad” apartments. I tested “SHOLTZ” LED Lamps.
7. The more flickering lamps in the room, the faster and more destructive the effect is.
8. The PWM may differ depending on the OS version of the device: e.g., iOS 17, iOS 17.1, iOS 18.
9. The PWM Frequency depends on the Brightness, and you can reduce the symptoms by changing the White Point value in the device settings.
   
   Also, some Android smartphones provide DC Dimming option to control the flickering, but of course, it’s best to buy the phone without PWM at all right away.
10. The only thing I can’t confirm in any way is the worst case in this situation that described in the following post on Reddit. The picture in the current post is taken from there. Judging by the screenshot, it was taken from the YouTube app, but we don’t have any information about either the study or the author.