There are two in one laptops and two in one programs! Dimmer Pro is such a program and I use it all the time! I work on a 27 inch high quality Dell monitor that is friendly enough to the eyes — yet who wouldn’t like even less brightness, provided of course that we are able to see things!

Dimmer Pro keeps the currently active window as bright as you have adjusted your monitor to be, making all the other open windows and the wallpaper darker, to a degree of darkness you can select from its menu, starting from 030 (in which case the difference between inactive windows and the active is hardly noticeable) and getting up to 255 when complete darkness surrounds the active window, just like if you had a monitor the size your active window.

If you combine the Dark mode of Dimmer Pro with Taskbar Control, you can make also the taskbar invisible, this way seeing just the active window and nothing else.

Dark mode is great if you want to minimize monitor radiation, but it’s not a mode you can use if you need to see information displayed in more windows besides the active one. Usually I prefer the first 3 modes (030, 060 or 090) to reduce brightness, protect my eyes, focus on the active window where I work, but also keep viewing things on inactive windows. Using the (customizable) keyboard shortcut of Dimmer Pro you can bring up its menu, select dim levels or undim everything and return to regular view.