Brightness on 24" Apple Cinema Display Using Windows 8.1

I'm using a Lenovo Twist running Windows 8.1 with a 24" Apple Cinema Display that has the Mini-Displayport connection. I am trying to figure out how to dim the display if this is possible. There are no external brightness buttons on the display, and I am slowly going blind early in the morning at work. Are there any plugins possible or a backdoor kind of solution to adjust the brightness settings? Any help would be greatly appreciated!