The display used in the Samsung Galaxy S23 Ultra is undoubtedly excellent. It has a peak brightness of 1,750 nits with a 120 Hz refresh rate.
But its display has a hidden downside that many are unaware of. I am talking about Low Pulse-width modulation (PWM).
What is PWM
PWM is a technique that rapidly turns the screen on and off at a certain frequency to create the illusion of dimming. You can compare it to a ceiling fan.
While this may save battery life and reduce heat generation, it also creates flickers that can be harmful to your eyes.
Problem with S23 Ultra
Nowadays, PWM technology is used in every smartphone display. But a higher PWM frequency is not as dangerous as the lower one.
Unfortunately, the Galaxy S23 Ultra has one of the lowest PWM frequencies among all brands of mobile phones.
![S23 Ultra with 240Hz PWM](https://ntpor.com/wp-content/uploads/2023/04/IMG_9341-1-1024x597.jpg)
It only uses PWM at 240 Hz, which is lower than the 480 Hz of the iPhone 14 Pro. Even Chinese mobile phones use PWM at 1000 Hz or higher.
The Galaxy S23 Ultra’s display may damage your eyes more than other phones with higher PWM frequencies and lower modulation depths.
Especially if you use your phone in low-light conditions or for long periods of time. You may experience symptoms such as dry eyes, blurred vision, fatigue, or even photophobia.
Tips to protect your eyes
So what can you do to protect your eyes from the Galaxy S23 Ultra’s flicker? Here are some tips:
- Use your phone at a high brightness level. This will reduce the modulation depth and make the flicker less noticeable.
- Turn on Night mode or use a blue light-blocking app
- Follow the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds. This will relax your eye muscles and prevent them from getting tired.
That’s it for today. Always stay updated with our tech blog ntpor & stay safe.