Everybody looks cool in IR! This is my friend Anthony. The polymer (plastic) used in glasses lenses is opaque at these IR wavelengths (one-five microns). InfrarRed (IR) light is emitted by objects around us, but we can't see it. If the light is intense enough, we can feel it because of the rise in temperature it causes. A good example of this is the heat lamps used in fast food restaurants.