ClickMonitorDDC

ClickMonitorDDC is a Windows app to control your monitor(s) brightness.

• Reduce eye strain at night
• Minimal memory usage (4 Mb)
• Changes brightness directly on the monitor. No overlay. Compatible with the monitor’s settings menu.
  (any monitor with ddc/ci/cec - most monitors since 2005)

download and install it from here
https://github.com/chrismah/ClickMonitorDDC7.2

more advanced than Monitorian.
I prefer Monitorian’s minimalism.