How can I lower the brightness of my display more than what the buttons allow?

[HairlessHare]

I have two displays set up. One Asus mx239 (as my main display) and my old LG e1941 as an additive. I use the LG to display my Bittorrent downloads and CPU & GPU temperature etc. Just to glance at it from time to time. I've lowered its brightness as much as possible so it doesn't distract me.
I also like gaming at night. But now i have a problem. Last night I was playing Resident Evil on the mx239 and as you can imagine there were lots of dark environments. The LG felt like a torch but the brightness doesn't go any lower.
Is there a software that can help me out? and no i don't want to turn it off while gaming.
I'm using win10 / 980Ti

 

[Archaic59]

Ever consider something like this?

http://www.officedepot.com/a/browse/antiglare-and-privacy-filters/N=5+590989/

 

[ThatVietGuy]

Have you tried using Nvidia's control panel?

 

[Solandri]

http://lmgtfy.com/?q=windows+screen+dim+app

If the problem is backlight bleed (i.e. the LG monitor is displaying pure black, and it's still too bright), try getting some rolls of gray or brown cellophane gift wrap from a craft store. Cut it to size and tape it to the front of your monitor. Use multiple sheets for increased dimming.

 

[HairlessHare]

Have you tried using Nvidia's control panel?

Yep found it.. In Adjust desktop color settings.
The other apps wouldn't let me choose between monitors. Thank you