True night vision devices no longer use infrared and haven't for about thirty-five or more years. Instead, they use electronics to gather in what light there is and form images from that. An early example of this was the "Starlight Scopes" used for sniping and survelliance in Vietnam.

Infrared-based vision devices are WW2 and Korean War technology, easily spotted because of the IR source needed. The new stuff, not needing a source of IR, is covert.