The light on your laptop provides illumination for you to see its display. You can adjust the backlight setting so it is brighter or darker. Some laptops have an ambient light sensor that detects the amount of light in the environment. When enabled, the sensor automatically adjusts the light on the display to a higher or lower level. Adjusting the display brightness and activating the ambient light sensor requires using certain keys on the laptop's keyboard.
Adjusting Light Brightness
Turn on your laptop.
Press and hold the function or "Fn" key on your keyboard.
Press the up-arrow key on the keyboard to increase the brightness and the down-arrow key to decrease it. Some models may require pressing the ""F5" or "F6" key to decrease the brightness and pressing the "F7" or "F8" key to increase it.
Ambient Light Adjustment
Make sure your laptop is turned on.
Press and hold the "Fn" key on your keyboard.
Press the left-arrow key. This action enables and disables the ambient light sensor on your laptop. This sensor is located along the bottom of the laptop display. Do not cover the sensor or it will set the display backlight to the lowest level.
As there are several different manufacturers and models of laptops, methods for changing the light brightness vary. Consult your owner's manual or contact the manufacturer if the above methods do not work.
You can only adjust the brightness on the laptop's display. Monitors and projectors attached to your computer cannot be adjusted through the laptop.