Review on Samsung Galaxy S21 5G - Factory Unlocked US Version Smartphone with 📱 Pro-Grade Camera, 8K Video, 64MP High Res & 128GB Storage - Phantom Gray (SM-G991UZAAXAA) by Ha Joon (Kim joon) ᠌

Unfortunately, I found out about it after the purchase, when after an hour of use I noticed that I had a headache, my eyes were very tired and for the first time in my life there was pain. Before that, I used a smart phone with an ips matrix and could calmly sit behind it all day. It turned out that the maximum flicker frequency in s21 is only 240 Hz, provided that >300 Hz is considered safe (at this level, the brain does not register a pulsation). At high brightness it doesn't matter, but the dimmer the screen, the more pronounced the effect. Yes, it affects everyone differently, but there are no such screens that are completely immune to harm. Samsung is very disappointed, I don’t understand why they don’t put normal displays, I would be ready to take more expensive ones, but it’s safer, most Chinese have matrices with much better PWM performance for this price. Having started to understand this topic, I found people's questions about PWM in modern Samsung models, to which the company's official answer was the same and stupid; they wrote about the blue spectrum reduction mode (which I turned on the first thing I picked up the phone) and the dark theme. As a result, you will have to sell the phone and take something either for ips (which are almost non-existent in the premium segment) or some Chinese for amoled.