A compact optical device used to superimpose an intensified infrared image onto a visible image to allow night vision. It can especially be used to make goggles to be worn under the visor of an aircraft or helicopter pilot's helmet. The device includes a combiner located in front of the
This device is characterized in that it includes removable indexing and locking devices of the light intensifier assembly on the stationary imager operating in combination with opening and closing control devices of a light shutter of said stationary imager in such a way that the locking
