Vietnam Red Night Vision and Demons Myth

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:

…the United States designed and built red night vision goggles. The theory was red night vision goggles would allow soldiers' eyes to maintain daylight sensitivities and more easily switch from day to night vision because red light does not force the eye to adapt to low light conditions…. Red light also stimulates the brain's neurons to increase reflex time and spatial awareness, he added.

The new goggles were issued to mostly airborne troops in 1965, and the whole bizarre episode took place over about 60 days... A week after the soldiers were issued the red night vision goggles, their behavior began to change. ‘The men started acting strangely, they started talking about things that nobody else could see... they were fixated at staring at treetops, then they started having discipline problems and actually began fighting among themselves.’

According to Anthony, a pivotal incident happened during a helicopter patrol over a relatively peaceful area of Vietnam when a gunner wearing the red night vision goggles opened fire at something at the same altitude as the chopper. ‘The gunner cried out he was shooting at demons, he kept screaming demons,’ Anthony reported, noting the gunner described the beings as horrible-looking, with horns, and flying toward the chopper. Officers and pilots had been ordered not to wear the red night vision goggles, but an officer aboard the helicopter ordered the gunner to remove his goggles and then put them on himself. ‘He saw several grotesque winged humanoid creatures flying up from the treetops below toward the helicopter,’….

This was not an isolated event. ‘For weeks, reports kept coming in about flying monsters spotted by soldiers who wore the red night vision goggles,’… Officers who disobeyed their orders and wore the red night vision goggles described seeing gargoyles or demons, and anyone who wore them indicated the creatures would come after them as soon as they saw them, he noted. Use of the red night vision goggles was abruptly canceled after 60 days. Soldiers who had worn the goggles were mentally unstable for months after the experience, Anthony revealed, adding the military has since switched to green light night vision goggles.

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.

In 1969, the Army used a goggle-type device, on a limited basis, as a pilot's aid in night flying in Southeast Asia. In 1972, the U.S. Air Force used SU50 electronic binoculars for night search and rescue missions.

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]

The device gave spectral form to guerillas who had previously seemed like invisible ghosts. In a sense it confirmed their phantom qualities by making them visible as otherworldly forms.

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.

Fatigue, stress, and fear exacerbated the tendency in some soldiers to misinterpret the images they saw through the scope…Even inanimate objects such as rocks and plants appears to be enemy soldiers advancing forward on the viewer. Soldiers described ‘dragons’ and other super natural creatures.

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.

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

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[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/