One of them can be replaced by a passive low-light-level night vision device or infrared sight.
Knock on wood ... The night vision devices worked well enough.
They can be thrown off course by pilot error and by clouds that obscure their vision devices.
The first military night vision devices were introduced by the German army as early as 1939.
The commander is provided with all round vision devices rather than the limited ones of the driver and gunner.
Such early night vision devices had many drawbacks, and the TKN-1 was no exception.
One common misconception among consumers is that night vision devices can be used in complete darkness.
Fifty yards away, an enormous dark spot on the hull, one of the ship's vision devices, swelled and darkened.
Aarn led the way, equipped now with a vision device, up to the level where his ships had been stored.
At the nose was the control compartment, and here the vision devices had been installed.