I can never see the things, and i’ve never been able to. Could someone explain to me in simple terms how they work?
Instead of focusing on the flat image, you have to kind of focus through the image to a point farther away.
I love Magic Eye calendars. I get one each year. (And it’s almost a new month! I can hardly wait to flip the page.)
Folow this link for both an explanation on how these things trick the brain as well as some advice on how to get to see them yourself.
For my part I have a very difficult time seeing the image in these things. My sister can spot the image in 5 seconds. I got a Magic Eye book for Christmas once and one day (bored) sat down with it determined to make it work. After about 30 minutes of futzing around with it I was able to see the images. Once I got one to work I was able to see the others in the book in fairly short order. After an hour screwing around with the thing I put it down and found my vision all whacked out from doing whatever it was I did to get my eyes to focus appropriately. Not anything permanent but it was annoying.
Start with a “noisy” pattern with lots of detail and not much in the way of solid fields.
Make it 50% of the expected width of the finished image, and copy it.
You put the depth information in the second image. The way you do this is by going over every pixel and assigning a value for its imaginary Z-axis (it’s depth.) When you have that worked out, you manipulate the image with that information. Say that pixel is at infinite distance. Then, you do nothing to it. If it’s in the extreme foreground, you place a pixel of the same colour over to the right, (say, arbitrarily, fifty pixels.) If it’s in the middle distance, you place a pixel of that colour over to the right twenty-five pixels. Repeat for each pixel.
Now you have two images, which look like chaotic patterns, but they differ based on depth information. You want to look at one with one eye, and the other with the other eye, tricking your brain into thinking you’re looking at the same image, and the differences are due to optical parallax. So you arrange the images on a single plane in such a way that makes it easy to do that by crossing your eyes slightly (or going ‘wall-eyed.’) Usually, the images are sliced into vertical strips and arranged ABABABAB.
I don’t know if you asked this question because of the “optical illusion” thread below, but I’m going to include a link to a [del]Magic Eye®[/del] Single Image Stereogram that I made today, using Photoshop. I know, I’m insufferable.
![a [del]Magic Eye®[/del] Single Image Stereogram that I made today](http://img64.imageshack.us/img64/9305/muddsis7un.gif){kind=link}
It’s just supposed to look like a 3D craggy/cavernous thing, so don’t waste brain cells trying to figure out what it is. 
Uh, that’s phrased a bit weird. That part is done algorithmically, of course.
Don’t worry there is nothing there to see. They are simply an elaborate trick to test the gullibility of people.
Thanks for the link, Whack-a-Mole. If I understand it correctly, it’s all related to depth perception and so needs both eyes working together. I asked this question because one of my eyes is kinda odd, and I was wondering if I’d actually be able to see these kind of images at all.
I’m not really sure how to get across what my odd eye is like…essentially, the pupil is a third the normal size and off-centre, and I have both poorer vision (i’m also reasonably shortsighted, so it’s both that and extra fuzzy on top of that) and higher than normal light sensitivity, to the point where it’s hard to keep open in normal outside light.
Does anything in that sound like it would have an effect? I don’t really want to waste my time trying to see these images if i’m never going to be able to, or if i’m going to see a distorted image.
I’m afraid so. With most of these images, you need to see fairly details with both eyes for them to work. If one eye is fuzzy, you’ll get nothing, even if your depth perception is fine with actual objects.
I did think that might be the case. Especially with this, which needs both eyes working together, one eye being out of whack is going to cause problems even if the other one were fine.
Ah well. I can still scare small children with it, and that’s the important thing. 
I’ve never ever seen anything in those things except mess!
The only way I can see anything is to look at them cross-eyed instead of “defocusing”. Unfortunately, the means:
1 - I see them backwards. That is, the bits that are supposed to be projecting are indented.
2 - I get eyestrain and a slightly nauseated feeling if I do it for very long.
That’s my issue. My left eye is far, far weaker than my right. So much so that if I were to lose my left eye in an accident, my depth perception would be unaffected – my right eye does all the work.
Needless to say, Magic Eye prints are useless to me.
…
“It’s a schooner!”
You can fix that by looking at them upside-down.
Of course, then they’ll be upside-down.
The Magic Eye things work by using an almost-repeated pattern that actually has slight shifts. The real trick is fixing things so that the offset-by-one iteration of the pattern has the slightly different left and right views that allow for a three-D image, then arranging for the next ityeration to show the right-left deviations relative to the first set, and so on. It’s a mind-boggling task, and I’m not surprised that development of these images had to wait until we had computers.
If you want to see the same general effect, try looking at a floor laid out with identical tiles, of the same size and shape. You can either do the cross-eyes or look-through gaze, but you’ll have your left and right eyes focussed on different centers. yet because the tiles are so similar, it won’t be immediately apparent. Of course, the pattern isn’t 3D.
If you want a 3-D pattern, hold a Slinky, slightly outstretched, close to your face. You’ll find that you can center your right and left eyes on different links", yet coalesce the image in your mind as if you were looking at the same spot. And the helix will be 3D.
As for the “look Through” vs. “crossed eye” vision, you can look at the same picture either way, perhaps with some practice. I find that I can do this. The very cleverest "Magic Eye picture I ever saw is of this variety – it’s the old “Vase or Two Faces” optical illusion, only done in 3D! If you look at it crosseyed it’s 3D faces, but look through it and it’s a 3D vase!
Sadly, my wife can’t see these. It might have something to do with some surgery she had on her eye muscles, years ago.
My depth perception is very poor, and I’ve never been able to see those things. Used to try something awful when they were popular. One eye has always been very dominant over the other (funny thing is, when I got LASIK the dominant eye switched sides, but I still don’t have any depth perception - my brain has learned to compensate all these years, I guess, and is not interested in learning a new trick.)
In principle you ought to be able to place an optical wedge over one eye to direct it to the correct place in the Magic Eye picture so that you don’t have to do the “look through” or “cross eye”, but when I tried it (I wanted to help Pepper Mill see the Magic Eye pix), it didn’t work. There’s a powerful tendency for the eye to try and see the picture as printed. So I haven’t had any success in my “Magic eye Viewing Glasses” development.
Screw that, just cross your eyes and you will see it.
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Screw that, just cross your eyes and you will see it.
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As noted above (in more than one place), with most such images, which you will see something, it won’t be the intended image. It will be an “inside out” (pseudoscopic, actually) image, that might actually be harder to correctly interpret. The “Look Through” method is, in most cases, what you need to see it properly.
Although the “cross your eyes” method will at least tell you where the image is and tell you its shaspe.
This is like riding a bicycle - I haven’t seen any of these for many years, but I got the “look through” technique back in under half a minute.
It’s a trick. One out of four Magic Eye pictures is packed with a sheet of paper saying “Shh! You have been selected as one of our Team Assistants. Do not tell this to anyone. Here is the picture you will claim to see.” (and there follows a small B&W picture of a doggie or whatever they can use to fake it) “Think of the fun you will have tricking people. The best part is when they claim they can see a picture that isn’t there!”
Seriously, though, when they first came out I could make out the pictures if I tried really, really hard. It was difficult, but it is pretty cool to have a ghostly image seem to materialize out of nothing.