The Flickering Laptop Screen
If you install Ubuntu Linux on a modern laptop, you may notice that your screen brightness constantly shifts while you work. When you open a terminal with a dark background, the screen dims. When you switch to a web browser with a white background, the screen painfully brightens. This is caused by an automatic brightness setting that attempts to save battery power by dynamically adjusting the backlight based on the ambient light in the room, or based on the content currently displayed on the screen. While efficient, this flickering causes severe eye strain.
How to Disable Automatic Brightness
You can turn off this dynamic adjustment natively in the GNOME control center, forcing your screen to stay locked at the exact brightness level you set using your keyboard hotkeys.
1. Open the main Ubuntu Settings application.
2. In the left-hand sidebar, click on Power.
3. Look in the section labelled “Power Saving Options.”
4. Locate the toggle switch labelled Automatic Screen Brightness.
5. Click the toggle switch to turn it Off.
Disabling Content-Based Dimming (Intel Graphics)
If you turned off the setting above but your screen still flickers when switching between dark and light applications, the culprit is not Ubuntu—it is a hardware-level feature called Intel Display Power Saving Technology (DPST). To kill this deeply embedded feature, you must add a kernel parameter.
1. Open your terminal.
2. Run the command: sudo nano /etc/default/grub
3. Find the line starting with GRUB_CMDLINE_LINUX_DEFAULT.
4. Inside the quotes, add this exact text to the end of the existing commands: i915.enable_dpst=0
5. Save the file (Ctrl+O, Enter) and exit (Ctrl+X).
6. Run the command: sudo update-grub
7. Reboot your laptop. Your screen will now remain perfectly static.