PWM Flicker: Why Your New Phone Hurts Your Eyes at Night

PWM dimming flickers your OLED screen thousands of times a second to look dim, which can trigger eye strain and headaches.

Low PWM rates like 240-480Hz are the worst; look for high-frequency PWM above ~1920Hz, ideally 3840Hz or more.

Cheap and mid-range OLED phones often use the lowest, most aggressive PWM — the price tag hides the eye cost.

Use the 'pencil test' or a slow-motion camera in a dark room to see flicker before you buy.

Look for TUV Rheinland Flicker-Free certification or a DC-dimming toggle if your eyes are sensitive.