About 15 years ago I had a monitor from Philips that had the ability to software control the backlight at a reasonably fine level (I don't recall if it was actually the same resolution as the display, but it pretended you could choose it per pixel).
The primary use case of the included software was to highlight the focused window and dim the rest. Other than that, it was more of a chore to use.
The primary use case of the included software was to highlight the focused window and dim the rest. Other than that, it was more of a chore to use.