An overly bright computer screen can lead to eye strain after extended use. If you can use your screen as a light source, then it is probably too bright, and you should dim the display. Most laptop computers offer hot keys that allow you to reduce the brightness without ever venturing into Windows' Control Panel. On desktop monitors, the Control Panel isn't usually an option anyway, but you can reduce brightness directly through the monitor's menu.
Look through your laptop keys for a "Fn" key or a dedicated "dim display" key. The latter is usually indicated with a picture of a sun with a down arrow next to it, or the sun icon might be hollowed out, giving the appearance of being dim.
Press the "Dim display" key to reduce screen brightness. You might have to press "Fn" at the same time.
Hold the "Fn" key and press the down arrow on your keyboard if you do not have a dedicated "Dim display" key.
Press the "Menu" button on your monitor.
Press the arrow keys to select "Brightness" and press "Enter" to select the option.
Press the down arrow to reduce brightness.
Press the "Menu" button to exit the menu, or simply wait a few seconds.