Not Everyone Can See Haidinger's Brush-Can You? 

if you are actually seeing it, it will tilt as you tilt your head. For me when I looked through the polarizer I saw blue the brightest and yellow was faint. But on the screen yellow was the brightest. This may be different for different people though.

Me, on my phone: I'm sure that was cool.

The Action Lab: "Not Everyone Can See Haidinger's Brush-Can You?" Me: No, but I will blame my monitor.

With the particular presentation in this video it's also possible that you're going to see a persistence aftereffect from having stared at the yellow and blue nodes.

I like your content, but I find it a bit polarizing...

Me with macular albinism trying to see it. Him: it occurs in the macula. Me: Oh, well damn.

When I saw "Includes paid promotion" I started to pray for not being Raid Shadow Legends.

The last time I was at an eye doctor's, I was able to tell the screen they were using was polarized because I've discovered that one of my eyes starts hurting when staring at polarized light in a dark room and everything starts to look weird with that eye.

Thank you for showing me how dirty my laptop screen really is

What's amazing about him is he has very good knowledge of biology, chemistry & physics and he knows how to use them

The "hey everyone" never gets old

Quick notice for people trying this on phone or tablet. Protective glass strongly depolarizes the light coming from LCD, so it won't work with glass screen protector.

As a child, I always stopped and stared at the puddle in the parking lot. The oil on the top made a polarizing effect. I tried to explain it to my parents, but they couldn't see it.

It’s important to note this might not work in OLED screens, as those don’t need to use polarisers. Furthermore, screen protectors usually scramble the polarisation due to them using a thin plastic film (if you look at a screen protector through a polariser you can see random multicolor interference patterns).

I've seen this around lights constantly since I was young. Around 12 years old I told my mom about it because I thought there might be something wrong with my eyes and she (being a spiritual lady) told me I see auraa. It's neat to have a scientific explanation for what I'm seeing, because I've never shared her spiritual explanation.

“Left polarized light, and right polarized light” Me: There’s a political joke in there somewhere. *Shows the light waves in red and blue* Me: Oh come on.

Me, when I saw that brush: Woah, I have a super power Me, after realising that it was an image: Oh....damn Me, after the image is gone: AM I BLIND?!

thumbnail: "can you see this?" people with High quality 8K Display : "yep clearly"

I actually noticed this when looking at computer screens more that a decade ago. I searched for “blue and yellow blob in vision” and got my answer. It’s always fascinated me that some (or most) of us can faintly detect not only polarized light, but the direction of polarization. Really cool. A 6th sense.

I love this channel so much b/c it reminds me of the early days of science communicator youtube. Every video is creative and discusses science topics I've never heard of before. These days, there are countless channels that just rehash what others have talked about already. Awesome work!

Me, on my phone : is this how you feel when you don't get the joke that makes everyone laugh?

"that is so cool" "holy cow" can never get old

I didn't see it, but I did notice a lot more floaters than I thought I had.

I wish this started off with an explanation of what "Haidinger's Brush" is.

Optical Engineer here, a lot of the light "information" here is not right. For example, metals do reflect and polarize light. There is a whole field of measurements "metrology" dedicated to thin films and metal polarization detection also known as ellipsometry. Linear polarizers dont work on circular or elliptically polarized light, instead, you need a retarder (compensator), quarter wave plate + a linear polarizer to resolve the polarization of light coming from a metal.

*[Macula]:* "You guys say 'Colorado!'" *[Eye Floaty]:* _"I'M A GIRAFFE!!!"_

5:17 The normal orientation, it's invisible, but I imagine the starting point is that the yellow line is vertical. If I tilt my head left, the yellow line tilts right, and if I tilt my head right, the yellow line tilts left. It's possible that it's invisible to me when level because I'm used to looking at this screen with a level head, so my brain just filters it out.

I can see it! Had to turn my head down 90 deg to see it better, but its there, about 1/2 the size of the one you started with.

I remember an Inuit guide describing a similar vision that he used to navigate in the snow. I was so crazy how these guys could get around in wast expanses of white with no landmarks before GPS and compasses were very bad in the Arctic.

If you orient your sunglasses correctly, *Rotates head*. . Driving 10/10

Pretty neat stuff. I use cross polarization all the time on VFX projects where we need to control which lights are producing specular highlights on objects that are going to be comped in with 3D animated elements. Each light source will have a polarizer that is aligned specifically for that group and the the camera lenses will have a circular polarizer that can be adjusted depending on the lighting group that is needed.

Wow! I couldn't see it at first, and then I got the test image to look more bright, so I tried again with the actual white image and I saw two yellow dots flip sort of diagonally! Cool stuff.

This is perfect timing! My wife and I were talking about polarized sunglasses and our kids asked what polarization is. This video explains it better than I did so now I can show them this!

I thought I was special till he took the image away.

oh my god i’ve been seeing this for YEARS and never had any idea what it was!!!! i’m diagnosed with HPPD and have extremely bad visual snow so because of that i always second guessed myself thinking it was whenever i was on a bright white screen it was causing like a tiny part of my visual snow to become way more noticeable (despite knowing from experience that my visual snow improves greatly with strong light and only gets bad and intense in low light) but it was unmistakably different and i’m so glad i finally have an answer!! it’s extremely noticeable on my monitor but i see it sometimes on my ipad too (never on phone) for anyone having trouble seeing it, keep in mind that for me at least the simulation he shows of it is a bit misleading in terms of its visual clarity and shapes, for me on my pc monitor when my head was in the normal vertical position i was seeing the blue as quite large messy circular shapes like an infinity sign, but when i tilted my head sideways to see the yellow it was a much thinner profile in comparison as it wasn’t as messy (still very vibrant though) thank you for finally giving me the answers to this extremely mild “inconvenience” that i thought was me just being crazy lol

That was actually amazing, I never thought I would learn something this weird about myself and then pick up on it within seconds of turning my head a few times. Now this is probably something I'm going to see all the freaking time!

Me: "I can see it, but the blue is horizontal." Video: "Which direction it is depends on how you're tilting your head." me, laying on my side: "Well there you go then."

All I could see was how dirty my screen was when I watched this on my TV.

Actually had a really easy time with this one :) Blue was horizontal, yellow was vertical, and the would each fade in an out, peaking as my head was perpendicular to the orbital

i used to see this thing all the time back when i used to be really concerned with my visual disturbances, i thought that was just another one of them!!! i saw it every time i rotated my phone. this is super cool!!

Everyone who can't see it: "Alright, then. Keep your secrets. 😏"

Family caught me staring at a white screen with my sunglasses on. Thanks Action Lab!

Ooooohhhhhh!!!!! That explains something I've always experienced! In some lights I've seen yellow or blue auras...

6:56 ooo.. what you’re talking about may be why I have great peripheral vision. I have always practiced seeing without moving my eyes or head. It helps so much to be able to look forward and in your side view mirrors (or rear view mirror) simultaneously when driving. Maybe this is different, but it sounds like it is using the same technique.

Yes. But if you are being honest it in part is based on the quality of the screen you are using.

This man looks like hes so sick of life yet he opens my mind to life

That's really cool. I never would have known that was something other than light play. Mine was 20% the size of the image you showed but visible.

👏🏼👏🏼👏🏼 Amazing!!! I always thought that was something on monitors, I never thought that's something about vision. I thought the yellow part was the light source of the screen and the blue part the areas where were not well lightened. I was looking to the phone and tilted a little, this gradient pattern doesn't fit the screen, because it was bigger, but it changes direction, going to the opposite direction from where I started to tilt. Love this experiment!!!

I have been noticing something yellow in my field of view for about a year now only with my iPad on white background when reading. It was quite annoying, I though it was old age and my eyes were going. But so cool to know what it is now. Thanks!

I actually saw everything, though the yellow was relatively clearer to me than the blue

I have one eye through which I see clearly, after having 7 ops on the other one for retinal detatchment which see but doesn't focus. So, I can see tons of yellow but not the blue, and that's with no sunglasses. Thanks for sharing this, I saved it to favourites!

While I didn't see the Brush, I did get the thought to turn my polarized sunglasses and WOW when it dimmed that white background (at around 45 degree tilt) I saw all the spots on my monitor! Thanks for this new tech.

I can see it perfectly without the polarizer.

This is the moment I realized I've always seen it but never paid attention

I have two different model screens. One had the yellow horizontal the other had it vertically. That was very interesting.

Now I can't unsee it. Very cool!

Great, another thing that I can't un-see. Someone showed me how to see all the "floaters" one day, now they're with me for life.

This is indeed like unlocking a superpower, cool.

I saw it on my tablet. Reminds me of the "Magic Eye" technique. Also saw I need to clean my screen.

I could see the yellow as clear as day, but the blue was like thinly stretched watercolor. (Without polarization)

i’m kinda really glad this channel went mainstream. it’s used to be like my guilty pleasure of learning bout random sciency nerdy things, now the comments are flooded with meme replies and inside jokes and action labs lore, lmao. i love it. feels like a hidden gem i like is being shared w the world (in a good way)

I’ve always been able to see this. This has actually been a problem though. LED headlights really mess with my eyes.

Well thank you for making me clean my screen, i saw it too, its smaller than i expected and then yellow was much more noticeable than the blue, neat.

lol, i recently watched the polirisation phenomenon when sitting in the car and watching the lights with and without glass, finally i understand, thx for sharing

What he meant by "Not Everyone Can See" he meant people with their blue light filters enabled.

this is what they use on cameras while filming shiny surfaces

I accidentally discovered this a while ago, but I thought it was just my sun glasses being funky. Had no idea this was a normal thing. Super cool.

That’s a bush? It just looks like 4 large dots

Me: trying to see it Video: "it occurs in the macula" Me: with swollen optic nerves "ah."

I got a headache after watching that metal reflection... It was as if I was staring at the sun 😂

Drink every time he says “polarizer”

It’s really hard to make out but it becomes a bit more clear to me when I tilt my head left and right

Instructions are wrong, ended up activating mangekyo sharingan.

I really like your voice it is so chill… you should do a podcast

I could see it very nicely. It does tilt with your head tilt which almost throws you off at first till you realize that's how it is intended. 20/20 vision here.

First I didn't see anything but the afterimage, but after some tries I got it to work. For me the yellow bulbs are horizonal and they actually tilt.

Y'know, this would be *really* interesting if he actually explained what polarized light is! :D

POV: you can both see the blue and yellow at the same brightness regardless of orientation *I am several universes ahead of you*

No way! Is that what that thing is? Whenever I've seen it in the past I've just ignored it, assuming it was just a relic of looking at something else. Like if you stare at an image long enough and then look at a blank wall and see the negative of the image you were just staring at. That's amazing!! Thanks!

Years ago, I had a pair of sunglasses that were both polarizing and UV filtering. Because of this, it could block the glare from some things, but the from the things it couldn't (sun glare off water) had this day-glo royal purple halo. Very pretty, I miss them.

I can see it, its smaller than I expected. I could only see the horizontal yellow.

Video Idea: Do the opposite where you show how to find your blind spot by closing one eye, extending your arm, stick out your thumb, and move it away from the center of your vision until when you wiggle your thumb, you don't see it.

Very interesting. I'll look at this tomorrow on a computer screen, but playing this on my phone when you display the image of what it should look like, I see only the yellow until I focus slightly away from centre. Then the blue appears. I can then refocus and see the blue, until I look away and back again.

Reminds me of the 3d “relax your eye” things. Though after a second the blue I didn’t notice at first in the thumbnail was there and wouldn’t go away, lol. ❤ your vids btw

me finding out not everyone can see this: visible confusion

So was there anyone who DIDN'T see anything?

Remember reading in a book a suggestion that vehicles could use polarised lights & have polarised windscreens to help reduce glare, always wondered if it would work. 🤔

I was actually able to see it on both computer screen and newer phone, it actually showed up better on my phone than on computer screen.

I just started messing with a polarizing filter on my camera and this made me realize why the filter can still be turned after being screwed in. Don’t know why I didn’t realize it sooner. Thank you.

Damn wish I had a polarizer for my Nintendo ds so I could see the screen in the sun

What does it mean if I seen both colors by just looking at the thumbnail and not clicking on the video but my wife didn't.

In my case, they were not vertical and horizontal, they were a little bit in X form. And the blue and yellow switched colors as I tilted my head (when I tilted right, yellow was \ and blue /, but when tilted left, yellow was / and blue was \).

It's amazing how much and how little you can see with your own senses.

Me first seeing the polarizer in action: Wow, imagine if there was like something you can wear that would just block all the glares on screens Me like a few seconds later when he gets to the phone: Crap I just accidentally reinvented sunglasses

I saw this effect a few years ago in a similar experiment 😊

Yup, I can see it on my phone's screen when it's vertical... very cool, thanks. I just realized I've seen this on my monitor before but didn't know what it was.

What’s odd is that I instantly saw it from the thumbnail but it did give me a bit of a headache from looking at it.

It's a little fainted but still visible.

This was such a cool video and science experiment. I could see it very faintly if I rotated my head towards my left. I loved this video so much I liked it twice!

I wear glasses, and could not see it at first, but after re-watching I heard you said it can depend on the angle of your head, I rotated my head and I could see it so clearly! I'm assuming my glasses must mess with the polarisation in some way...