PWM (Pulse-Width Modulation)

PWM dimming controls display brightness by rapidly switching pixels on and off. At low brightness, the flicker frequency (typically 240Hz or lower) can cause eye strain, headaches, or fatigue in sensitive users. Not all displays use PWM — many IPS monitors and LG OLED TVs use DC dimming instead. To detect PWM: dim the screen to 20%, wave your hand rapidly in front of it, or use a phone camera in slow-motion mode. If you see stuttering or banding, PWM is active.