The Flashing Keys Distraction
Modern MacBooks are equipped with an ambient light sensor that constantly monitors the lighting conditions in your room. While this sensor controls your screen brightness, it also automatically adjusts the backlight of your keyboard. If you work in a room with inconsistent lighting—such as near a window where clouds frequently block the sun, or in a room with a flickering television—your MacBook keyboard will constantly dim and brighten itself in the background. This subtle, pulsing light just beneath your fingers can be incredibly distracting when you are trying to focus on typing.
How to Disable the Automatic Keyboard Backlight
You can turn off the ambient light sensor’s connection to the keyboard entirely, allowing you to set a fixed, manual brightness level that never changes on its own.
1. Click the Apple logo () in the top-left corner of your screen.
2. Select System Settings (or System Preferences on older versions of macOS).
3. In the left-hand sidebar, scroll down and click on Keyboard.
4. Look for the section labelled “Keyboard Backlight.”
5. You will see a toggle switch labelled Adjust keyboard brightness in low light.
6. Click this toggle switch to turn it Off.
Setting Your Manual Preference
With the automatic sensor disabled, you now have complete manual control over the illumination. You can use the physical F5 and F6 keys on your MacBook keyboard (or the dedicated brightness sliders in the Control Center in the top-right menu bar) to set the exact brightness level you prefer. The keyboard will now remain locked at this exact setting, whether you are sitting in pitch darkness or bright sunlight.