Night Vision Goggles

Night vision goggles are optical devices that allow the user to make the best use of available light and/or through sensing normally invisible infra-red.

In Call of Duty 4: Modern Warfare
AN/PVS-7B night vision goggles are available to the player in many levels of singleplayer, and are always available in multiplayer. During the campaign, they can be used in conjunction with the AN/PEQ-2A laser to see a visible path a bullet will take, which can help with accuracy in some situations. However, this will not work to predict the path of a second bullet fired from the hip will take due to recoil. These may still fly anywhere within the crosshairs. Using these devices in a dark environment gives a great advantage over opposition, although they can be bulky and cut down peripheral vision. Light flashes from firearms and flares are more powerful and disorientating. They are only particularly useful twice in the campaign: once in the mission Blackout, in the house where you rescue Nikolai, and once in the mission The Bog, during the fight in the first building.

Night Vision is also available in multiplayer, but there are not many areas where it is needed. It may have some use on the maps Wet Work or Bloc, if the player's television's brightness and contrast settings are too low.

Call of Duty: Modern Warfare 2
Night vision goggles make their return, but are not used often in either single-player and not at all in multiplayer. It seems to have much more contrast, the lit areas glowing profusely, making it especially hard to look at. The only time that they are a major use is in The Gulag, when night vision is needed to infiltrate the dark bottom cells until they find light again. It's seen again in Just Like Old Times, only being useful for a few engagement with Shadow Company in the caves, but its use isn't particularly needed. Night vision goggles can also be used in the Spec Ops level Overwatch, but they are not particularly useful. In multiplayer, they have completely disappeared, probably because of the introduction of the Thermal Scope being so useful in dark areas and when smoked, with the fact there are no dark maps ingame.

Call of Duty: Modern Warfare 2 Prestige Edition
Working night vision goggles are set to be for sale with the Prestige Edition of Modern Warfare 2, the most limited edition of Modern Warfare 2. They are supposed to look like the NVGs In Call of Duty 4: Modern Warfare, as modeled by Captain Price before Gaz cuts the power during the mission Blackout. Interestingly, on the box for the NVG's it says, "Issued by Griggs."

Trivia

 * In The Gulag if the player switches night vision goggles on right before Roach is hit by debris and Soap fires a flare, the player cannot turn them off and must complete the mission with them on.
 * On the Xbox Live marketplace, you can buy a pair of Night Vision Goggles for 240 Mircosoft Points for your avatar to wear.
 * As said above Xbox players can buy Night Vision Goggles for your avatar. However when the first mapack for Modern Warfare 2 came out the user can get the Night Vision Goggles for free. But, it was for only a limited time.
 * In Call of Duty 4 multiplayer, when the goggles are switched on they can not be seen on the game characters eyes.
 * If you jump while pulling the Night Vision Goggles up, you can see the mount for a VERY short time. This can easily be done in Slow-Mo.