Stereograms are three-dimensional shapes that pop out from a two-dimensional image — and are a lot of fun to find!
How to view a 3D Stereogram
Normally, when we look at or read something on the computer monitor, we aim your eyes directly at the surface of the monitor, like this:
With the parallel viewing method (a.k.a. the divergence or Magic Eye method), the lines of sight of your eyes move outward toward parallel and meet in the distance at a point well beyond the image. When you parallel-view, the muscles inside your eye that control the focusing lens relax and lengthen.
Another 3D viewing methodis called cross-viewing or the cross-eyed method. You aim your eyes so that the lines of sight of your eyes cross right in front of the image. When you cross-view, the muscles inside your eye that control the focusing lens contract strongly and shorten. Just don’t try too hard!
If you’re not trained to look at stereograms, it might take you some time to be able to see 3D images quickly. But with time, you can master it. First time I’ve looked at a stereogram it took me like an hour to finally be able to focus the eyes correctly to see the 3D image.