The argument seems trivial, but for those who need to change the brightness of the computer screen frequently, because they use it at various times of the day or in different environments, depending on whether there is a lot of light around or if you work in a room dark. In this second case it is never advisable to keep the brightness high so as not to tire or make the eyes water.
Lowering the screen brightness can also be very helpful in saving energy and increasing the battery life of your laptop. Furthermore, in addition to the possibility of manually change the screen brightness, you can make the brightness be changed automatically based on certain factors such as: whether the laptop is plugged in or not, whether the battery is full or nearly empty, whether there is a built-in ambient light sensor that detects, as in mobile phones, whether the environment is bright or dark.
You can also use some programs to automatically adjust the brightness of the monitor depending on the time.
To manually change the brightness of a laptop screen you should find buttons on your computer keyboard. Generally this adjustment is done with the Fn keys plus the F7 or F8 keys. If they are not, just find the sun icon or something similar on the F1 to F12 keys at the top.
In Windows 10 You can also adjust the brightness of the laptop screen by clicking battery icon in the notification area near the clock, setting the brightness to maximum if you choose "best performance" and to minimum with energy saving. By going to Settings> System> Battery, you can activate the automatic power saving when the battery charge is low; this will also decrease the brightness of the screen, automatically.
The brightness of the monitor can also be changed (in Windows 10) from the Settings -> System> Display menu, using the dedicated slider. In this set of options you can also activate the night brightness, which allows you to automatically darken the screen from dusk to dawn.
In Windows 7 and 8.1, to change the brightness of the monitor if there are no hotkeys, you need to open the Control Panel, then go to Hardware and Sound -> Power Options where you should find the slider that adjusts the brightness of the screen at the bottom of the window .
On these older laptops, you can even open the Portable PC Center where you can find the slider for adjusting the brightness. To find the Mobility Center, you can open the Control Panel or press the Windows-X keys or, in Windows 8.1 and Windows 10, right-click on the Start menu.
How to manually adjust the brightness on an external display.
On Desktop PCs or on any monitor connected to the laptop, the brightness of the screen can only be changed by the physical buttons of the monitor itself.
Then find the power key on the screen next to it. the Menu / Options button or directly those of the brightness to change it and set it as you prefer.
With some monitors you can too adjust the screen brightness with a PC program like ScreenBright or as Display Tuner, both free and worth trying.
On Windows 7 the program can also work iBrightness, to change the brightness of the screen with the mouse and also to turn off the monitor with a click.
PangoBright instead it is a simple and small program to change the brightness of the screen in percentage, always at hand.
DimScreen is a small portable program to dim the screen with hotkeys or change the monitor lighting from the keyboard, both on laptops and desktop computers.
As mentioned at the beginning, on laptops It can automatically adjust the brightness when depending on whether it is plugged into the power outlet or if it runs on battery.
Windows uses standard energy saving profiles, the default being the balanced profile.
Here you can configure different levels of brightness of the laptop screen with a higher level when connected to the mains and lower when powered only by the battery. These options can be found from Control Panel> Hardware and Sound> Power Options, by clicking on the "Change combination settings" link next to the activated profile (the balanced one if nothing has been changed).
To automatically change the screen brightness according to the remaining battery charge you can use the Windows 10 battery saving mode, under Settings -> System.
Here you can activate the option that minimizes the brightness of the screen when the battery is low.
By default, Windows 10's battery saver feature lowers the screen brightness when the battery is only charged to 20% (but this can be changed).
However, there is (for now) the option to choose which brightness level to lower it.
Automatically adjust brightness based on ambient light this is only possible on some computers with a light sensor. Many new laptops and all tablets have this ambient light sensor which works in a similar way to that of smartphones.
Windows can use the adaptive brightness sensor and automatically increase the screen brightness when in a bright area or decrease it when in a dark room.
To activate or deactivate this feature in Windows 10, open the Settings application -> System -> Display and activate the option to automatically change brightness according to the ambient light.
In Windows 7, 10 and 8 the same option is in Control Panel> Hardware and Sound> Power Options, by clicking on "Change combination settings" and then on "Change advanced power management settings"
From the "Display" section, click on "Enable adaptive brightness".
In this case it is also possible to choose whether to activate this option only when the computer is running on battery or always.
Finally, a program such as F.Lux to adjust the brightness and color of the screen according to the time.
Alternatively you can also choose to use the night mode on the screen.