Night vision has recently become a point of contention (or has been before and I didn't realize it). While night vision doesn't grant you some cloak of immunity to death, it can help you in almost every situation that requires you to see in the dark without the use of white light.
Let's first talk about how night vision works. Night optical/observation device or NODs are used to amplify ambient light to a large degree, helping you see where you otherwise would struggle. One of the first things people do when they put on NODs are look up at the sky, and gawk at how many stars they can see. You have 3 main generations of night vision.
Generations Of Night Vision
Generation 1 night vision was invented in the early 1960s, and used as the starlight scopes in Vietnam. These were very bulky, heavy, and required a lot of moonlight to use properly.
Generation 2 night vision was developed in the 1970s and when you started getting head mounted devices in the form of the AN/PVS 5. Once again these were very heavy, bulky, did not offer good peripherals, and the actual image intensification they offered was not wholly sufficient to use on dark nights.
Generation 3 started development in the 1980s and is still used today to a large degree. That's where you have the AN/PVS 7, PVS 14, and other scopes.
Generation 3+ is what we largely use today. You can have Gen 3+ PVS 14s, and that's what most binocular night vision devices (BNVDs) are, such as AN/PVS 15s, 31s, and quad tube GPNVG-18s.
As a general rule, you should only be purchasing Generation 3 or Generation 3+ NODs. Not only for general capabilities, but they're also going to last longer and will maintain their resale value much better. Don't try to save a few bucks and buy Gen 2.
How many tubes do you need?
We generally look at the number of tubes as more = better, but there are pros and cons to both. Unfortunately getting quad tube GPNVG-18s is largely unattainable for the majority of people trying to see in the dark on their own dime, so we won't focus on these too much.
Dual tube night vision goggles (DTNVGs) offer you a lot of benefits over a single tube, but there are also some slight cons. Some of the main benefits of DTNVGs will be better peripheral vision (wider field of view), and better depth perception. It makes sense, you're looking at the world with two eyes instead of one. This depth perception really comes into play while driving or navigating poor terrain. Passive aiming is also easier in theory, since the two eyes open will be easier to find the reticle and put it on the target before pulling the trigger. Another large benefit to running certain dual tube setups is that you can move the tubes to sit further apart, rotating above your eyes instead of stowing them up on your head. This is going to give you less neck fatigue over time if you're running them on your helmet for a long time. Not something that will directly give you more or less capabilities, but adding the additional weight on your head will start to add up quickly, especially when the balance isn't optimal.
PVS 31s stowed up.
Single tube setups are generally found in the form of PVS-14s. There are alternatives to the actual L3/Harris PVS-14, but they're largely copies of the 14s. The PVS 14 has been in use with the US military for years, and is still largely in use.
The advantage of a 14 over a DTNVG setup is primarily going to be cost, though I've found that having one eye that is adjusted to the darkness helps when you need to flip up your tubes. Your naked eye will help to see colors, and if you're using a magnified optic you can put the tube over your support side eye and shoot with both eyes open to essentially "passive aim" with a magnified optic like an ACOG.
Having an unaided eye to be able to keep your natural night vision keeps you from having to adjust your eyes in the event that you cannot use your tubes anymore for whatever reason. It's entirely necessary to give your eyes a break after a while, and prolonged night vision use can result in headaches, but this will also be more or less likely depending on your personal setup.
You can also bridge two 14s together to create a dual tube setup, and there are products that can flare them out to almost simulate the peripheral vision of quad tubes without the venn diagram effect that you get from GPNVG-18s.
Bridging two PVS-14s together can be useful due to being able to disconnect one to lend to a friend, having two separate units in case one gets damaged, and flexibility with setups (can take one off and mount it to your rifle for night shooting), and you can gradually buy the parts instead of one bulk buy. But these setups are oftentimes heavy, and if your tubes are different specs then it may be noticeable while using both at once, unlike DTNVGs where the tubes are made at the same time with the same specs.
Another question that often gets asked is "White Phosphor or Green Phosphor?"
Note: white phosphorous kills people, and white phosphor is the color you see in your tubes. There are no white phosphorous tubes.
WP tubes were first given to pilots to help them work for long durations without fatigue, and to help see details better. WP tubes will generally be pricier, but will allow you to see more at once due to how the receptors in our eyes work. You will also have less eye fatigue over time and will be able to go longer under NODs before you start to get headaches or sore eyes.
GP tubes are still by in large the standard, and they are completely suitable. Green phosphor was originally chosen because the human eye can distinguish more shades of green than other colors, so with early generation night vision it was easier to see details and create an accurate image of the world in your brain.
GP tubes are generally going to be cheaper, and it's not uncommon to find DTNVG green tubes for the same price or slightly more than a WP single tube. The advantage you get over using DTNVGs vs a 14 is much higher than WP over GP.
The main methods of mounting NODs are going to come in the form of bump helmets, ballistic helmets, and the Crye Nightcap style setup. The Nightcap will offer you the most airflow and is easily stowable while the helmets will provide protection at the cost of weight and air flow.
The Crye Nightcap
The Crye Precision Nightcap is essentially the baseline for mounting. It provides no protection from bumps or ballistic threats, and can be worn comfortably. Since these are easily stowable in a pack or pocket, you can have them in your night vision kit without having to figure out where to cram a helmet in your pack if you don't want it obvious you have a helmet. This is beneficial for hunting, hiking, general stargazing, or low profile operations where you do not want to highlight yourself as a combatant.
Bump helmets are lightweight plastic shelled helmets designed to protect against hitting your head. These were originally made popular by Delta Force and other teams that were doing a lot of high speed CQB in the 80s and 90s, and would use modified skateboard helmets to fit their mission needs. They were more concerned with hitting their heads on something than being shot, and the helmet offerings at the time (PASGT) were heavy already, with poor ballistic protection.
Modern offerings from Ops Core or Team Wendy are much better than the old Pro Tec skateboard helmets, and are generally cheaper than ballistic helmets. These are beneficial if you are on a budget, or are more worried with carrying your nods and comms/ear pro while doing long unarmored movements or working in rocky/mountainous terrain. Some of the new offerings from Ops Core are bump helmets that can protect against light fragmentation and small handgun rounds while maintaining their low weight and air flow.
Pro Tec bump being utilized in the early GWOT
Modern Ops Core bump helmet with the works on it
These are generally the standard today with most that will put themselves in harm's way. Ballistic helmets will counter the threat of most handgun rounds, fragmentation, and even rifle rounds. The NIJ rating system for helmets is a little goofy and largely goes with the measurable back face deformation after getting shot with certain rounds. That being said, many people have taken rifle rounds directly to the head and survived with either minor bruising or ringing ears and no long term injuries. Modern ballistic helmet offerings from the larger brands like Gentex, Ops Core, Team Wendy, MTEK, and Crye will be overall lightweight for the advantage you get, and will obviously offer more protection where it counts. Surplus (and current issue) full cut ACH's and ECH's are still a viable option, and will still do the job. These can usually be bought for a cheaper price. I would be weary of getting a full cut helmet with the intention of converting it to a high cut, since that can damage the ballistic integrity of the helmet.
Delta Force Operators 2004-2005 with a mid cut helmet (left) and full cut helmet (right)
Crye Airframe Helmet
US Marines testing high cut ECH helmets from Gentex. Notice NVG mounts on helmets with night vision stored away
Here's the main meat and potatoes of this. The prior info was more for you to decide what will work for you, and making some of the terms you see thrown around more clear. Let's get into it.
Once you decide what night vision setup will best work for you, you now have to use it. Buying a $2000 PVS-14 will still give you the baseline capability to fire and maneuver effectively at night compared to those that do not have NODs. There are two main methods of aiming your rifle at a threat under night vision.
Active aiming is utilizing an IR laser to point at targets. Active aiming is generally quicker than passive, but will potentially give your position away to the enemy. With IR lasers, you can only see them under night vision. They are not visible to the naked eye. IR lasers are also very useful for marking targets and for guiding fire.
Using active aiming for close quarters battle (CQB) is extremely efficient. You don't need to worry about giving away your position to the enemy when you're in the same room as them and prioritizing speed and violence of action over concealment.
There's a huge rabbit hole with IR laser devices, but the main units people will use are surplus PEQ-15s, PEQ-16s, Steiner DBALs, OTALs, Zenitco Perts, or the Holosun LS321G. There are also units like the BE Meyers MAWL, and a ton of other IR units that are generally reserved for those with big wallets. If it can maintain zero and has a high power or focus, it's generally good to go. Most civilian lasers are limited due to laser restrictions, but surplus or imported lasers can be purchased that are full power.
Many decent units are combination IR Lasers/Illuminators, but cheaper units that are only lasers are still a good option for active aiming.
Passive aiming is looking through your optics with your night vision, and not potentially giving away your position with a laser. Generally for passive aiming setups I'll recommend using a Surefire M600V, which is an IR illuminator only. Think of a flashlight that can only be seen in the IR spectrum. The Surefire M600V is a dual head where you can twist it to be white light (visible), off, or IR. Due to the nature of LEDs and the IR spectrum, these lights tend to lack on the white light side compared to the M600, which is a dedicated white light.
Passive aiming capabilities will depend largely on your optic. Magnified optics generally struggle due to focusing on the reticle and light transmission. This is why I generally opt to use Aimpoint/Holosun/Sig red dots, or Eotechs. The Eotech window and holographic reticle is very easy to acquire your reticle and keep it crisp. Most optics now have "night vision settings" which are just extremely low brightness settings that won't bloom under NODs. If you can take your optic to the lowest dot brightness and it doesn't cover up the entire target at 50m, it's probably fine. This is also why you see a lot of 1-6x LPVOs with an offset red dot. You cannot feasibly aim passively with an LPVO.
I mentioned before that you can put your tube over your support side eye, and shoot both eyes open with a magnified optic on strong side eye. This can work, but will not work as well as a dedicated red dot for passive aiming. Generally piggybacking will help with passive aiming over an offset red dot, but there are pros and cons to every setup like most of us have figured out by now.
Auto-gating is a feature in modern night vision that adjusts your image intensifier constantly. If a bright light is shined at your tube, the auto-gating will turn down your intensifier so you do not get blinded, or get an overload of light in your eyes. This is especially useful for fighting in urban areas with street lights, vehicles, light up billboards, and all of the other fun stuff we get to stare at in the metropolis. This is why somebody shining a light in your face, or turning on a light will not suddenly blind you like in the movie Step Brothers.
Putting It All Together
So we've picked out a night vision device, now we need to be able to actually put it into play through the three primary pillars of shoot, move, and communicate.
Shooting is the first thing everybody thinks of. We've covered passive and active aiming, and now we've outfitted our rifle according to our needs, budget, and what capabilities we want. We have a basic setup with a Surefire M600V and an Eotech EXPS 2-0. We've found that it's a bit easier to shoot with it on a Unity riser, so we have our raised optic to help maintain a more upright position while shooting, and to help with lining up the tube and optic.
Now we need to train. Something that most find difficult to do is reload. So we go into a room, turn off the lights and close the blinds, and start training speed reloads and tactical reloads. Retaining magazines and dropping them to quickly feed the gun. Then we train bringing the gun up to getting a quick sight picture/sight alignment for up close. Later on we save up and get a laser unit for our gun. We bring the gun up from the low ready and shine the laser on the target. We do these reps to get the natural feeling and learn how our gun can become an extension of ourselves.
Now we put it into play. Shooting targets of different sizes, shapes, and distances. Throw some no shoots in there to train PID while your visibility is limited, and colors don't show as well.
While we're shooting, we realize that the super cool compensator we got for an ultra low recoil 5.56 gun is absolutely terrible for flash, so we put a flash hider on it. These are all things that you will find come into play while actually going out and testing your setups. You also find that steel causes a much brighter muzzle flash then brass. You fine tune your setup to get the best balance of daytime fighting and nighttime fighting.
Since you bought a PVS-14, your depth perception is slightly off. What looks like a small dark patch along the road is actually a ditch. You train to recognize what certain things look like, and you've gotten to the point where you can move efficiently at night, until the new moon starts. You make it part of your intel before a trip to check the moon phase and cloud coverage. You check the foliage of the area you'll be in, and what time of year it is. You study satellite maps to determine if the place is littered with evergreens or has deciduous trees that will be leafless by now. All of this goes into your mission planning. You go out one weekend and find that it's a new moon with cloudy skies and thick canopies. You figure out where your gain should be on your tube for different environments, and train to practice IR light discipline. If an enemy sees you shine an IR light, they'll know you also have night vision capabilities and will change their plans accordingly.
It starts raining so you include a microfiber cloth on your kit to wipe your lenses. All of this will come into play for moving quickly and efficiently, as well as seeing where your friends are and adjusting formations properly for the terrain in the nighttime where only a few of you may be able to see passed 4 feet. Going through the woods or taking the path are both used, and your route planning is much more efficient due to being able to see key features and obstacles, even at midnight.
You stack your formations to have guys with night vision in the front, back, and center with putting guys without this capability in between them. Now your team leader has to pull rear security, and you have to do many more counts when you stop to ensure all your guys are there. These adjustments are being made to be most efficient with limited technology and capabilities among your guys.
The often overlooked pillar. Now that you can see at night, you can more efficiently see who is out of formation (they can't see), and can pass word to them to adjust. Everybody has cat eyes on to help you see who is friendly and who isn't. You can see the callsign patch of the guy in front of you to help your movement techniques, and when you finally reach your objective, you're able to get a better picture of the target area and can jot down the notes and pass word efficiently to your friends. The ones without night vision are unable to see the target area 100yds away, and are waiting for word.
Putting on night vision doesn't automatically make you a god, and should be taken with the same attitude as owning a gun. You have it, but still need to train with it and practice. Your mission planning will drastically change, and your capabilities will skyrocket if you have the technology and the training behind it. Think of it this way, a trained guy with a bolt action rifle will outperform an untrained guy with an AR-15, but a trained guy with an AR-15 will outperform both at the same time.
Don't limit yourself in the ever changing arms race that we have to keep up with on our own dime. We all make different amounts of money and have different circumstances, and while guys shouldn't be excluded because they're college students barely making ends meet, keeping up with this arms race is something we should strive to do. When optics became regularly available, there were still people that were pushing for iron sights. Once they used the optics they realized how much faster and easier making accurate hits is. We need to treat night vision the same way. It gets dark every night, and using the cover of darkness to effectively shoot, move, and communicate will only help increase your percentage of success.
While the LRRPs in Vietnam, Rhodesian Selous Scouts, Army Rangers in WW2, and shock troops of WW1 didn't own night vision, neither did their adversaries. The Taliban had to greatly change their tactics and still lost tactically in almost every engagement that they fought. If any of the previously mentioned forces had night vision, they would have an undeniable advantage over their adversaries, and would have been able to increase the skill gap between them and their opponents. Don't look at previous wars fought before this technology was readily available to determine your priorities. If this were the case, you wouldn't have an optic, white light, or half of the gear you own. The year is 2022, and we have to keep our fighting capabilities up to date, or we cannot guarantee our survival against those that have kept their capabilities up to date.