Xiaomi has introduced the increasingly popular DC dimming feature to its flagship Mi 9 via the latest MIUI update. The new 10.2.27 firmware has begun rolling out in China. Other improvements include stability enhancements and new power-saving optimizations. Once you update your Mi 9 device you will get a toggle for the new anti-flicker mode from the display section in the settings menu. Xiaomi claims the new option will allow for better eye protection and should reduce visual fatigue at low brightness levels thanks to the decreased screen flicker. According to Xiaomi's software...
Source: https://www.gsmarena.com/miui_10_update_brings_dc_dimming_to_xiaomi_mi_9-news-37384.php