Visible invisible light

Ok, this may sound really weird, but I am trying to find a combination of things.
I want to find a particular wavelength of light (give or take some) that is invisible to the naked eye...and if possible, I need to find a way to allow that light to be seen by wearing special glasses.
The special glasses should be able to be worn without any major discomfort, like a regular pair of glasses, and they should allow the person to see his or her normal surroundings without any change. The only difference is that they would be able to see that other particular wavelength of light without any problems.
It would have to be a wavelength that is not already highly in use and possibly bouncing around, like infrared (from cell phones and what-not).
I want to be able to shine a light and have only people wearing certain glasses be able to see it.
I guess it would be a good thing to make sure the wavelength I use is SAFE for humans to be exposed to it for prolonged periods of time. (2-3 hours or more)

If this makes sense to anyone, and anyone has any suggestions, please feel free to let me know.