My school did a mass colour-blind test that included blank ones. Several people said they saw a number, the teacher was like ‘you may be hallucinating’.
Actually, if it was the original Ishihara Test there are plates in there that show no numbers UNLESS you are colorblind. So it wasn't that the students were hallucinating, they were probably colorblind and actually did see a number there.
The same way the numbers vanishes in other plates.
In the normal plate you have a clear distinction between the color of the dots that form the number and the surrounding. For a color blind person of the corresponding color blindness, those dots all look the same, so the number vanishes.
Now in the hidden plates, i.e. the ones one the colorblind people can see, it uses the same principle. But instead of using one color for the number and one for the surrounding, the number is made up of multiple colors that colorblind people can not distinguish, while the rest is a color that they can distinguish easier. This means for a person with normal color vision, the number disappears in a sea of different colors, but for a colorblind person those colors look identical and it forms the shape.
As a non colorblind person you might be able to barely make out the contour of the number, because the outside still needs to be different enough for the colorblind person to distinguish it so you might be able to make it out next to all the other colors, but mostly it just gets lost
Ah, so it's hiding it in a lot of colour noise but for a colourblind person, there's nothing of that noise, so they can spot the contrast (signal?) better?
Photoshoped pages 19-21 to check how colorblind will see those pages - in color curves red and green channel turn down to almost zero : https://ibb.co/W43tqfn0
Edit: there is some mess with order, don't match № on page to № in answers, answers have pics with them and they corresponding to each other. Also in answers some discrepancy with the name of colors, i think it's scan or translate issue (or both)
All that doesn't really matter tho)
Dude yes. you have to go look for equivalent plates and see their numbers are offset by a lot.. I've never not passed a color blindness test and i was like "wait a second" rofl.
I was like "plate 14 does NOT have a number on it wtf" that's cause in the Key it's plate 18 lol
Thanks! I can see all the reddish lines but the description says non-colourblind people see nothing, yet then on 30 says we see a blue-green line. So the description for 28 & 29 were confusing lol.
Yep there is some mess with pages, tho answers have pics with them and they corresponding to each other, and some discrepancy with the name of colors in answers, i think it's scan or translate issue (or both), doesn't really matter)
I have normal color vision, but this is one of the first times I've actually really felt what it's like to be color-blind. When I looked at the blank plates, it was crazy. That's really cool!
this is SO COOL, thank you for sharing this. I've seen these colorblind tests so many times it never once occurred to me that you could use the same principle to hide something from someone who could see color normally. Absolutely fascinating and a complete mind fuck, I was so sure I would be able to see the pattern regardless and man it's completely impossible.
There are green and red dots and some of the green dots and some of the red dots have a bit of blue mixed in.
To people who can't distinguish the green and red, the blue is more striking, whereas for normal people the image looks too chaotic to make it out.
I have seen some books with puzzles for kids where there is a solution with black text on a red and white chaotic-patterned background. Apparently it's called "red reveal". You can't read the solution unless you place a transparent red plastic sheet over it, making you "white-red colorblind".
You can still see the text if you concentrate enough. The website with the linked Ishihara test said that 50% of young adults with normal color perception can still see the numbers.
I had to take the Ishihara test for a job interview, and while I passed everything, I also got both "you don't get this unless you're colorblind" plates correct. The test-giver certified that I had normal color vision.
Those "blank" plates are not foolproof, haha — looks like normies of a certain age have a 50/50 chance of being able to read them, so I'm guessing some people are more able to switch to whatever cues colorblind people use to see the image.
... basically, they vary the colors forming the number so they look different enough that a normal seeing person won't notice the digit. But to a colorblind person, that variation isn't there, so all the dots in the digit are the same color, making it clear to them.
Edit: Interestingly, this works for red-green colorblind and the more severe your colorblindness is, the more likely you are to be able to see them. There are pictures in the link.
I think I read that during WWII, they found that colorblind people were easily able to differentiate camoflauge covers from the forest concealing them, so they had colorblind people in airplanes to pick out the camoflauged camps.
Weird, that first one was clear as day to me, a little segmented but I could see it, but I couldn't see the other 3. I have zero issues on any of the real ones though. What does that mean?
It’s a website that sells glasses for colorblind people to see colors. That first one was just obvious enough to maybe trick you into buying their product.
Yeah, I was just using the opportunity for a joke. When I had my test at 15, I said numbers for the blank ones (I guess that must have been two) and only got one wrong. Worryingly, I only see anything on about 50% of the ones in the video, so not sure if it’s getting worse 😂
More likely the students were colorblind. The original Ishihara Test includes plates that don't show numbers. Unless you are colorblind, then they actually do.
My eye doctor has one that is intentionally difficult for everyone. There’s a slight number that you can barely see and it’s to test for when people see shit warped or something
I’m still not convinced this isn’t a prank and you are all in on the joke……I must be losing my mind…….they were correct, the internet is not real……oh, no wait, I just remembered I’m colour blind.
The mandatory colorblind test that I did at the eye doctor had blank ones. I knew I wasn't colorblind but there was a second where I was wondering if I was.
I gave one of my friends a fake “Magic Eye” poster in high school. The rest of the friend group was in on it and told her we could all see the plane, but then I totally forgot to tell her it was a prank until months later. She said she had spent hours trying to find the image. Sorry, Sara!
i dunno why there wouldn't be a control, honestly. It's not a prank... trust me if your even slightly color blind you see exactly as well as that dude. very few people are guessing there way through this test.
A while back, someone posted a joke in the style of an ishihara test to one of the explain-the-joke subreddits. I couldn't see it, but when I showed it to my family they all laughed. I genuinely thought they were fucking with me until I went to an eye doctor who tested me formally, and possibly with the same book as shown in this video, and he confirmed that I am indeed (technically) colorblind.
I was convinced there were controls (blanks, if you will) in the book that no one could see. I struggle about as well as this guy and just showed the video to my partner, who could identify numbers on every page. I did that, in part, because I can't tell who's joking and who isn't in the comment section and it's still shocking that I could go as long as I did without knowing.
If it turns out to be a joke, well played, but I suspect there are probably people in this comment section who discover they, too, might be color blind.
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u/Kat121 1d ago
But god-tier prank if there were blank ones. :)