Night Vision Goggles are extremely rare tools that are used to see more effectively in the dark. They take up their own slot and can be used by pressing 'N'. Weapons that use iron sights or otherwise lack scopes are fully compatible, but the only scoped weapons they can be used with are the DMR and the M16A4 ACOG.
Because Night Vision Goggles work by amplifying ambient starlight, sudden bursts of light (such as flares or chemlights) can render their users temporarily blind. It is possible to use them in low-to-mid light conditions (such as near sunrise or by flares), but their users must wait for their eyes to adjust upon both donning and removing the goggles.
Night Vision Goggles can be found at either the barracks at the northwest airfield, or randomly in a Helicopter Crash. The pilot zombies that are unique to helicopter crashes have a very small chance of carrying them as well.