You may have heard the urban legend of early or experimental “red” night vision goggles used in Vietnam allowing users to see interdimensional beings like ghosts or demons. The following is one account of the urban legend given by the Coast to Coast AM radio show of July 8, 2023 with guest Mark Anthony:

While to anyone who understands any basic scientific information about how night vision works would immediately recognize this as implausible, it has not stopped retellings from going viral on TikTok.

Various spurious claims with just a little scientific truth mixed in to sound plausible to the ignorant have been made. One claim was that a chemical dye, Dicyanin, a toxic dye, was used in the early NVGs. It leaked out and caused hallucinations. However, dicyanin is not known to have psychoactive properties that would induce hallucinations even if they somehow were used in otherwise red goggles. Group hallucinations of the same phenomenon over a period of time are improbable because typically each persons’ hallucinatory experience is different. So what if it was the dicyanin that allowed people to see the spirit realm like a sort of visual filter?

Walter John Kilner, eccentric author of The Human Atmosphere, researched the idea of the human “aura,” or an electromagnetic field around the body. Kilner used dicyanin tined glasses believing that the resulting tint altered light to reveal the aura. The problem is that dicyanin is a blue tint, although he did use carmine red glass in his experiments. So assuming that the dye somehow allowed one to see the spirit world, this variation of the myth can’t even get the colors right!

Actual veterans have destroyed the rumor. Several pilots from that era have confirmed that there were no red NODs at that time, let alone goggles for flight crews. Extremely rare SU49 and SU50 goggles, which became the AN/PVS-5, date from the late 1960s and used green phosphor tubes. The near-prototype goggles were only used on an experimental basis and on the highest profile, top-secret operations like the Son Tay raid.

These early devices used low-sensitivity tubes, were heavy, and cumbersome and not adopted. Even the improved PVS-5 was hated for its bulk and incompatibility with cockpits.

There is no evidence or record of the US military ever having used red night vision. Nonetheless, this doesn’t mean that they secretly actually didn’t, nor that demons weren’t spotted. Being top secret, of course this kind of thing would be hushed up and all proof of red NVGs and their disturbing revelation covered up. For anyone who sincerely believes that, there is no convincing them otherwise.

For everyone else, the story has just enough truth to give someone with the vaguest understanding of night vision the impression that it’s true. A pseudo-intellectual explanation appealing to an uniformed audience might appear to make sense. It’s easy for someone with limited scientific knowledge to conflate the color red with the infrared spectrum. After all, red light helps preserve night vision, doesn’t it? If nighttime lighting is supposed to be red, isn’t that the best color for NVGs? But it also makes sense that people would see demons because red is an “angry” color.

While red does help preserve night vision by causing the slowest bleaching of the light-sensitive chemical rhodopsin in our eyes, it’s not a good choice for color displays. In 1995, Nintendo released the Virtual Boy, a virtual-reality headset that turned out to be a commercial failure. Perhaps one of the reasons it failed was its red-on-black monocolor screen.

Nintendo used only red LEDs due to cost, producing a monochromatic red image that resulted in players complaining of vertigo, nausea, and headaches. One reviewer said “the red was frankly kind of hard on the eyes.” Others were annoyed or disappointed with the screen. Whether it was the monocolor display, the color red, or other reasons, the Virtual Boy did not succeed.

Red as a color for augmented reality should have been seen as a poor choice simply from a psychological standpoint. Red is traditionally associated with strong emotions and is considered an attention-grabbing color. It can also stimulate physical responses, such as increased heart rate and blood pressure. Research in color psychology has indicated that red is associated with heightened arousal. It’s absent from most lighting, except in narrow military contexts. It’s often used in film to create tension or fear and to unsettle the audience. Red is an unnatural color, not often seen in nature, except usually as a warning.

Red phosphor tubes do exist. They are fairly recent developments and very rare. Most were developed for trials. As far as any published, unclassified source shows, red tubes were never used operationally by the US military. In fact, it doesn’t seem like they were ever really used in any serious research. Every commonly used phosphor screen has been a shade of green. Only the thermal imager, the AN/TAS-4A used with the TOW Missile launcher, used a red and black LED display.

Phosphors are used in screens, such as in early cathode ray tube (CRT) displays, because it has the ability to emit light when struck by electrons. In these screens, a beam of electrons is directed onto the phosphor coating inside the screen, and when the electrons hit the phosphor (luminescence), it glows, creating the visible image. Phosphors are ideal for night vision applications also because of their persistence; the light emitted from phosphors lasts just long enough to provide a clear, continuous image without overwhelming the viewer’s eyes or causing excessive afterglow.

While it’s true that any phosphor could generate the images, not all are suitable. Red phosphor tubes do exist and many different colors of phosphor were developed and tested during the early development of display screens, red was only adopted in certain niche applications. Red phosphors were more prone to burn-in and degradation over time compared to green phosphors. Green phosphor was also brighter and more efficient, while red had issues with persistence, meaning that the image quality was often poorer.

Green is simply a better color from a both spectral efficiency and human visual sensitivity perspectives. Yellow-orange-red light is not the optimal color for sensitivity in low-light conditions; green is. Red screens would produce a suboptimal image. Parts of the image that reflect red-orange light may appear less distinct or blended with adjacent colors, leading to a loss of contrast and detail. In a way, this would be like colorblindness.

Green phosphors often have better persistence characteristics, meaning the glow lasts just long enough to create a smooth image without excessive ghosting or flicker. Red phosphors, by comparison, may not offer the same level of smoothness in certain applications, especially early on in development.

The first documented US use of red phosphor in night vision dates from 1987 where a mix of red and green tubes was used in the Chromatic PVS-5 goggle. The goal was to create color night vision by using binocular fusion, except experiments were unable to produce true-color views. Later experimentation was tried in the 2010s and red phosphor tubes were briefly available in limited numbers around that timeframe by special order. It’s not so much that red phosphor tubes never existed, it’s that their documented development was later than the Vietnam war.         

Some of the collectors who obtained recently made red tubes posted images and they are certainly striking, perhaps even unpleasant to look at. While on objective terms they perform equally to P43 green tubes, perhaps subjectively they appear slightly darker and have less contrast. It probably wouldn’t be anything anyone would want to spent the night looking at. The color would likely exacerbate the psychological aspects of night combat. Whether red or green night vision, probably the mind that is most responsible for any perception of evil.

An article published in 2017[1] is often cited as “proof” of the stories, is anything but. Rather, the author clearly documents that the optical illusions variously described as “dragons,” “ghosts,” etc. were the product of unfamiliarity with night vision, fear, stress, and fatigue. None of the accounts seem to seriously suggest the user believed they were seeing the supernatural.

[1]

Soldiers and Marines, who grew up with black and white TVs, were unaccustomed to seeing the world through night vision and to them it may have seemed a little like magic. “Soldiers who spent ling nights peering into this strange electronic topographical arrangement began to see it not so much as an altered version of the landscape before them but another world…” The low resolution of early tubes didn’t help the otherworldly appearance. Some users reported being “bewildered” by jungle phosphorescence or shadows from flares and may have mistaken this as apparitions.

There was also the psychological burden of “seeing” the enemy who became less of a vague figure and as another human, not merely a target.

We’ve been conditioned by film to see red as a bad color, so would it be surprising if someone subject to the intense stress and fear of combat, coupled with anxiety, might be spooked by a red image? Even the few side-by-side comparisons of green and red phosphor tubes make the red ones look “bloody” and unpleasant. Red, therefore, is probably the worst color for night vision. Not that there actually were any red NVGs in Vietnam at the time, but if there were, it might be unsurprising to find that spending an entire mission looking at the world in red would produce anxiety.

This was an excerpt from The Night Vision Manual - Book 1 Image Intensification, a comprehensive guide to night vision.

[1] Richard A. Ruth, “The Secret of Seeing Charlie in the Dark,” Vulcan: The Journal of the History of Military Technology, 2017

Images taken through the tubes of red and green phosphor NVGs. Courtesy of J.W. Ramp.
https://www.flickr.com/photos/jwhairybob/47493171282/in/photostream/
https://www.ar15.com/forums/armory/Let-s-See-Some-Red-Phosphor-Christmas-Tree-Night-Vision/18-498793/

We actually didn't shoot, despite putting targets down range. Why? No cans, for one. Two, the idiots were actually so close we thought it would be rude to start shooting in the darkness. The morons would have probably been utterly terrified that we were shooting and they would have no idea we had everything under control while wearing NODs.
 
Second, we also had a thought that they might be homeless or at least boondockers, and while fucktards who camp at any time, night or day, on a BLM shooting area, don't deserve any courtesy, disturbing homeless car campers who aren't shitting up the city itself would be too inconsiderate of us.
 
Third, they were outside the ricochet zone but they wouldn’t know that. Also, unlike during daylight shooting, there would be no way to see them and one of the dumbasses might be out in the moonlight without a cheap flashlight to mark their position. Might be bad.
 
Finally, we were up-moon from them, meaning we were backlighted. If they felt threatened and were armed, they had a clear silhouette of us.
 
 
Discretion being the better part of honor, we packed in the targets after we played around with the different settings without firing a shot. I established a rough converging zero on that Somogear fake PEQ-15 I picked up. I have some questions about the illuminator (IR laser flashlight) but need to try it on a moonless night.
 
One thing we noticed that under the monocolor of NODs, a white painted steel target doesn't really stand out. The lasers will reflect off it though.
 
 
So we went driving in the darkness on desert roads. Driving IS possible with a monocular like the PVS-14, but there are a couple of caveats.
1. We had a full moon. Great contrast and the shadows weren't really deep.
2. We left before astronomical twilight was over, meaning there was a lot of sky light available.
 
If you have both eyes open and enough ambient light, your brain will fill in the image well enough to give you some depth perception. I had issues keeping it "between the lines" so to speak but otherwise did fine. Got up to 80 on some sketchy roads. Pretty sure hearing a truck blasting by a high speed in total darkness freaked out the 'tard campers.
 
Also when driving at night you gotta cover up the instrument cluster and turn off the dash iPad, I mean the stereo screen. This isn't a Crown Vic or Tahoe where you can just hit the blackout button.
 
The nice thing about being the driver and wearing NODs is, that unlike my limited professional experience with them looking for agricultural thieves, I can control the vehicle and didn't get seasick. With more practice a passenger shouldn't have this problem either, assuming the driver isn't a jackass or a bad driver.
 
 
As far as my personal PVS-14, well you can see I need to get a better photography solution for it than holding an iPhone up to the eyepiece. The three camera system in the iPhone Pro sucks for this kind of thing.
 
Also the halo (ring around bright lights) are why I suspect this otherwise flawless tube was kicked from the military line to the civilian side. NV tubes for civilians are the ones for the military that don’t make the grade for some reason or other; not quite “rejects” but that’s literally what the engineers call them. All ITT Pinnacle tubes of that era had a noticeable autogate whine but I’ll take that over a big, splotchy black blem any day.
 
 
Lastly, I think I need a 2.26” riser for proper passive shooting through my red dot. The 1” riser didn’t cut it, and the 1.93” was a stretch. BUT the biggest issue was one of focus. NODs can’t really focus on everything like your eye. You can focus to infinity, put on the day cap for a pinhole effect, but neither will make the red dot and the target come right into focus.
 
Again, I’m late to the passive shooting party so I need practice, but I’ve read that focus and aligning a monocular behind the red dot can be challenging so it’s not entirely me. No, active IR won’t get you killed; using it stupidly and without discipline will. But that’s for the book. 😉 Otherwise, it was pretty easy to get the rifle at least up and on target, especially with the laser.
 
And yeah, that Somogear was WAY brighter than the Steiner COBL CQB laser I was using. I could see the dot but not as clearly and it too slightly more mental effort to recognize it. In full moonlight or ambient conditions, I’m going to have to pony up some money for a proper IR laser.
 
Video taken of the valley through the PVS-14 itself using an iPhone.

A link to the Twitter thread if you want more video.