And the night-vision systems built into the helmets of the mercenaries gave them almost full vision.

This far down, he wasn't going to be particularly visible to the guards, who did not use night-vision systems.

He stood near the tent flap for several minutes, turning slowly and looking around, the night-vision system of his helmet giving him an excellent view.

Even the best night-vision systems did not give sight quite equal to daylight.

Have you got your night-vision system turned on?

The camera technology, of course, is just part of a night-vision system.

His night-vision systems showed lots of activity on the ground.

Their night-vision systems would allow them freedom of movement and action.

Each column had to be led by a Di-rigenter with the night-vision system built into his battle helmet.

Even when friends and enemies alike were equipped with efficient night-vision systems, the darkness gave some cover.