In recent times, I have had to spend too much time in front of the computer screen. Unfortunately, my eyes didn't like it very much, and I felt strained after 15-20 minutes of work. Therefore, I decided to buy a new monitor, specifically one without flickering (PWM backlight). As it turned out, the problem was deeper than I thought. Most modern monitors are illuminated by backlight, and the brightness changes with PWM (Pulse Width Modulation).