Skip

Yellow-Tinted Night Vision Sunglasses? WTF?
October 18, 2010 9:36 AM   Subscribe

Yellow-tinted night vision sunglasses? Do these things actually work as advertised?
posted by Cool Papa Bell to Grab Bag (18 answers total) 2 users marked this as a favorite
 
They don't amplify light, only cut down on some kinds of glare from headlights and streetlights. Which part were you asking about?
posted by Burhanistan at 9:38 AM on October 18, 2010


Inasmuch as they might cut down on oncoming headlight glare, maybe. Dunno about the rest.
posted by jquinby at 9:39 AM on October 18, 2010


Also, first Google link says that while they might reduce glare they also reduce available light so they're not considered safe.
posted by Burhanistan at 9:40 AM on October 18, 2010


Which part were you asking about?

Do they actually improve your night vision? Not by amplification, obviously, but perhaps through some focusing / clarity / glare-reduction / removal of magic wavelength voodoo.
posted by Cool Papa Bell at 9:41 AM on October 18, 2010


> Do they actually improve your night vision? Not by amplification, obviously, but perhaps through some focusing / clarity / glare-reduction / removal of magic wavelength voodoo.

Layman's answer would be that the yellow tint creates an illusion of brightness that registers in the brain as such. But, there's no actual gain of magnitude.
posted by Burhanistan at 9:43 AM on October 18, 2010


i have astigmatism and i found that wearing my great grandmother's old greenish yellow tinted sunglasses at night greatly reduced glare. it was kinda weird. i lost them so i can't wear them anymore, but i remember being shocked at how much easier it was to see the road markings on dark roads.
posted by sio42 at 10:05 AM on October 18, 2010


While I'm not sure I believe much of the following, this is the explanation I've seen from a couple of sources:

Our eyes are most sensitive to blue light* so information our eyes get from blue light, especially the blueish background haze around dusk, can drown out the intensity/shading information from other parts of the colour spectrum. Yellow tinted glass blocks or reduces blue light, but allows the rest of the spectrum to pass unimpeded. So the idea is that while the total quantity of light getting to your eyes is reduced, the quality of the colour-independent shading/light intensity information you're getting is markedly improved. The picture you see is comparatively a bit darker but contains much more shading and fine detail, letting you pick out traffic etc. more easily.

As I said, I'm not sure how much of that I believe but it's the explanation I've heard from a few places, including the people who make my mum's yellow glasses. She swears (or swore; I'm not sure whether she still uses them) that they work for her and that she can see much more detail with them, especially when looking at clouds. I can't perceive a difference, but I've never actually tried driving in them.

More plausibly, I can imagine them actually helping to cut the glare from blue-tinted halogen headlights in oncoming traffic. Maybe that's a factor?

*I can't swear that this is true; I've heard it a lot, but never seen it backed up by a reputable source. I do know that we're quite bad at focusing blue light, as our eyes' lenses are better set up to focus the longer wavelengths of green-red light. This is why blue LEDs and violet/near-UV lights can look a bit weird, hazy or just generally difficult to resolve at night.
posted by metaBugs at 10:39 AM on October 18, 2010


Our eyes are most sensitive to blue light*

*I can't swear that this is true;


Apparently (heh!) it is not true.
posted by Kirth Gerson at 10:57 AM on October 18, 2010 [1 favorite]


When I wear my yellow safety glasses while using power tools outdoors in the afternoon, I often don't notice how dark it's gotten until I take them off — and then the effect is amazing, they really seem to make more usable light available somehow. I originally theorized that they enhanced some frequency that the iris was reacting to, so that my eye was letting more light in of other colors — but there's no lag time, if you take them off and put them back on it's just can-see, oh-it's-dark!, can-see-again. So maybe metaBugs' explanation is correct.
posted by nicwolff at 11:01 AM on October 18, 2010


I have terrible night-vision and dark, rainy drives with headlights coming at me are terrible. For a while I had a pair of yellow-tinted sunglasses that definitely made a difference (positively). They weren't purchased from anyone making promises though, just cheap crap with a yellow lens.
posted by HopStopDon'tShop at 11:21 AM on October 18, 2010


As I said, I'm not sure how much of that I believe but it's the explanation I've heard from a few places, including the people who make my mum's yellow glasses. She swears (or swore; I'm not sure whether she still uses them) that they work for her and that she can see much more detail with them, especially when looking at clouds. I can't perceive a difference, but I've never actually tried driving in them.

I'm not sure why yellow-tinged glasses increase visual acuity, but they certainly do -- there's a reason why most shooting glasses are yellow or orange. They create a very noticeable effect on the range... maybe not so much that you'd notice in daily life, but more than enough to make a difference when you're trying to pick out a target at 100 yards or more, especially near dusk or dawn.

I've got a pair of sunglasses which have a similar yellow effect, and have noticed the same thing your Mom has when driving (also especially with clouds -- the other day I came around a hill toward some previously-unseen clouds and was quite struck by their stark detail, which went away the moment I took the glasses off). They're sunglasses, though, so I can't speak to how they work for night driving...
posted by vorfeed at 11:28 AM on October 18, 2010


I've worn yellow-tinted glasses while shooting. One thing I've noticed is that they do increase contrast, obviously at the expense of color perception (everything turns yellow). Exactly how/why this works I've never been sure of, but it is noticeable if you're focusing hard on a high-contrast surface, like a black-on-white bullseye. It doesn't make it more visible as much as it reduces eyestrain and fatigue. They go in and out of vogue among shooters every few years it seems. I've also seen other colors of lenses, but the yellow seem to be the most common.

I don't really see how they would do anything about 'glare' ... to cut down on reflected light, what you want are polarized lenses, not just a yellow tint, but I've never seen polarized lenses that didn't block out a substantial portion of all light (i.e. were sunglasses).

Also, so many highways are lit exclusively with Hg-vapor lights, that have an orange hue anyway, that I'm not sure what purpose the glasses would serve. During the day I could see how they might reduce eyestrain, but at night they don't seem like a good idea.
posted by Kadin2048 at 11:31 AM on October 18, 2010


I keep a pair of cheap, yellow lens glasses in the truck. We call them the "happy glasses." When it is gloomy or rainy, put them on and you can't help but smile.
posted by I'm Doing the Dishes at 1:26 PM on October 18, 2010 [3 favorites]


Blue light does seem to be responsible for things like setting your biological clock, so I wondered if it might be involved in contracting your pupils, which could explain some of the observations people have reported in this thread, and I found a page advertising lamps with enhanced blue output, designed specifically to make your pupils contract, which said that it does:

Pupil sizes and changes were then measured remotely using thousands of data points for each subject. A near perfect correlation was found based on the relative sensitivity of the rods to different wavelengths (color) of light with the rods being most sensitive to the blue light spectrum. This sensitivity of the rods to blue light is also known as the scotopic response.

If blocking out the blue does make your pupils dilate, the yellow sunglasses could paradoxically be making more light available to the eye in many circumstances.
posted by jamjam at 1:56 PM on October 18, 2010 [1 favorite]


Low frequency/long wavelength light travels further through air, particulary smoky or smoggy air. That is why sunsets are red. It is also why you wear yellow goggles when skiing in fog or snow. So theoretically with yellow tinted glasses you are blocking out some of the scattered high frequency light, and seeing further into the distance. Why not do a test? Read a finely detailed sign in the distance with/without the glasses.
posted by weapons-grade pandemonium at 2:57 PM on October 18, 2010


I keep a pair of cheap, yellow lens glasses in the truck. We call them the "happy glasses." When it is gloomy or rainy, put them on and you can't help but smile.
posted by I'm Doing the Dishes


This is extremely intriguing.

With all the recent results showing that physiological conditions associated with emotional states can actually produce those emotional states even when those physiological conditions are externally imposed, such as the warm hands warm heart study showing that tricking naive subjects into holding a warm cup of coffee briefly leaves them strongly disposed to be more caring and generous, and the study showing that Botox injections actually sharply reduce the levels of the emotions they prevent you from displaying, if yellow glasses do indeed cause your pupils to dilate, and pupil dilation does indeed "indicate greater affection or attraction, while constricted pupils send a colder signal", then we may all be calling our yellow-lensed glasses "happy glasses" before we know it.
posted by jamjam at 6:43 PM on October 18, 2010 [1 favorite]


Not sure how, but yes they work. I am an eyeglass wearer and bicyclist, so I'm covered in the daytime when I wear my prescription sunglasses. I bought a pair of the wraparound style worn over my eyeglasses mainly for wind blocking when riding after dark. I was very pleased with the extra vision provided.
These things are so cheap, just try them and see for yourself.
posted by No Shmoobles at 12:06 PM on October 19, 2010


As kadin2048 said, they increase contrast.

That's the same reason ski goggles are tinted yellow and have some polarizing - to help enhance light and shadow.

They are not "night vision" in any sense of the marketing term, but they probably are appropriately "low-light contrast enhancing."
posted by carlh at 5:27 PM on October 19, 2010


« Older How can I find the 1 share of ...   |  What are some good books / mus... Newer »
This thread is closed to new comments.


Post