Use the monitor’s physical buttons or joystick
Open the on-screen display menu
Find the Brightness setting
Decrease the brightness level
Save or exit the menu
On Windows, open Settings
Go to System
Select Display
Adjust the Brightness slider
On Mac, open System Settings
Go to Displays
Lower the Brightness slider
Use your keyboard brightness keys if available
Turn on night light or blue light filter if needed
Enable auto-brightness if supported
Lower brightness in your graphics control panel if available