The invention regards an external vision and/or weapon aiming system for a military land vehicle and/or a military naval unit. The system comprises: two sensors configured to capture video streams of a same external scene, each in a respective spectral band; an electronic processing unit configured to insert a respective aiming reticle in the images of each captured video stream, thereby generating a corresponding pre-processed video stream, and to process the two pre-processed video streams; and a user interface configured to display a video stream received from the electronic processing unit. The system is characterized in that the electronic processing unit is configured to process the two pre-processed video streams by means of image enhancement and picture-in-picture functionalities, thereby generating first and second enhanced video streams.