Just like the previous generation of OLED-equipped iPhones, the iPhone 11 Pro and Pro Max both employ OLED panels that are prone to flickering that is particularly visible to those with sensitive eyes. The flickering is caused by PWM (Pulse Width Modulation), a technology used by OLED manufacturers to control display brightness. While both panels feature higher peak brightness compared to the OLED panel Apple used in the previous generations of iPhones, they are still prone to the same flickering at brightness levels lower than 50%. The screen flickering is particularly visible in low ambient brightness conditions, and may cause eyestrain with sensitive users.