You need to provide more information to get any good advice.
What caused the malfunction? Did you burn in the number because you didn't turn off your monitor or use a screen saver? If the number 6 etched into your glasses? With the information that you provide I can't give you an educated guess.
Sorry I'm not providing sufficient info...I do run a screen saver all the time, but it seems to be something I've hovered over with my mouse (does that make any sense?)...Such as my Magicjack splashscreen. When i hold my mouse cursor over the six digit on the splash screen, I see the same small 6, only the one is stuck for some reason. I recently downloaded the Dell Monitor driver from the Microsoft Website during an update, but I also have an NVIDIA graphics card if that helps any.