From the iPhone 17 series, Apple has introduced an option in the settings to switch off PWM. By switching off the institution is possible screen be prevented. This makes the device more suitable for PWM-sensitive users.
Unfortunately, there is a group of iPhone users who experience physical complaints while using their iPhone. Think of complaints such as headache, tired eyes, nausea and migraine. This is caused by the low PWM frequency of the OLED screen when it is dimmed.
If you are sensitive to this, there is finally a solution from the iPhone 17, iPhone 17 Pro and iPhone Air.
What is the PWM screen flickering problem?
The PWM problem is present on iPhones with an OLED screen. The brightness of the screen is arranged via pulse width modulation (Pulse Width Modulation) PWM abbreviated. The pixels on the screen are constantly switched on and off at a certain frequency.
At low brightness this is often accompanied by a relatively low PWM frequency, usually between 240 and 480 Hz. In some people, this can lead to a visible flickering or physical complaints, such as headache, tired eyes, nausea and migraine, even if flickering cannot be seen with the naked eye. The fact that this is a significant problem is evident from the popularity of the Subreddit “R/PWM_SENSITIVE” on Reddit. This Subreddit attracts thousands of visitors every week.
In the video above you can see the problem, some users notice this with the naked eye. The problem of screen flickering does not only occur with iPhones; All telephones and devices with OLED screen technology experience this when adjusting the brightness.
The ‘standard’ LCD screens used up to and including the iPhone 11 do not experience these problems because they apply higher PWM frequencies.
Turn off PWM on an iPhone
The iPhone 17 models, including the iPhone 17, iPhone 17 Pro and iPhone Air, have an accessibility setting with which you can switch off the pulse width modulation (PWM).
- Open settings
- Navigate to accessibility
- Tap ‘display and text size
- Switch off the ‘Making screen pulse (PPE)’ option
The following description is shown at the switch:
“This eliminates the pulse width modulation to dim the OLED screen in a different way, which can cause a smooth output at low brightness. When PPE is disabled, this can influence the performance at Lage Brightness under certain circumstances.”
DC-DIMMING: Full screen brightness adjusted
“DC-Dimming” will now be applied by switching PWM. Hereby the power to the screen is continuously lowered instead of switching the pixels quickly on and off, which ensures a quieter image. This method may use slightly more energy.
Turn off PWM on older iPhone models
Older iPhone models unfortunately cannot disable PWM, which leads to visual inconveniences such as vibrations or flickers on the screen. Apple has probably made hardware adjustments to make this function possible in newer models. They had to renew the technology for the screen lighting to improve the user experience.