Dilip Krishnan and Rob Fergus at New York University have developed a dark or invisible flash which uses infrared and UV light to take photos in dark places without the nasty glare of a standard flash. Their dark flash camera is made by modifying a flashbulb so that it emits light over a wider range of frequencies and filters out the visible light, and removes filters that prevent the silicon image sensor from detecting IR and UV rays. This flash results in a crisp image which does not have correct color balance, and looks like night vision photography
Here is the original post:
Invisible flash produces photos without glares