I did, for many years. It's one of those things that's hard to explain, and hard to do until you've done it, at which point you understand yourself then how to

I did, for many years. It's one of those things that's hard to explain, and hard to do until you've done it, at which point you understand yourself then how to do it. My father did magic eyes in the newspaper every week when I was a child, and I could never do it. I did start to wonder if he made it all up, but there was an answer key and he was able to figure it out, so there had to be something to it. Go to the paper: https://www.cs.waikato.ac.nz/~ihw/papers/94-HWT-SI-IHW-SIRDS-paper.pdf https://www.cs.waikato.ac.nz/~ihw/papers/94-HWT-SI-IHW-SIRDS... Go to figure 7, "Figure 7. Stereogram showing a hemisphere", on page 24. There are two black dots near the bottom. Cross your eyes: you should now see 4 black dots (2 per eye). Adjust how "crossed" your eyes are such that the "inner" two dots line up, s.t. there are only "three" dots, like `(dot) (two overlapping dots) (dot)`. Now, the hard part: your vision likely blurred when you crossed your eyes; without uncrossing your eyes, and maintaining the position/overlapping of the dots, bring your vision into focus. (This is, IMO, the hard bit.) Once I've got it into focus, I find my vision "stabilizes": I'm able to look around w/o having to concentrate on keeping my eyes crossed to a particular amount. At this point, I can look up above the dots, and there is a hemisphere in the image, as the figure caption says. This doesn't have to be done w/ magic eye images, either. Two normal 3d renderings of a landscape side-by-side, where the camera in one rendering slightly horizontally offset from the other, will also work. The idea is the same: overlay the images in your visual field, then bring it into focus. At least, that's what works for me. According to the sibling comment from chubasco, there's more to it, I guess, but the above is all I know.