We deal with 3D models all of the time, and when it’s possible to manipulate them in a viewer program, it’s relatively easy to get a sense of 3D objects from a 2D screen. It’s a lot harder with static images. That’s where cross-eye stereograms come in. All you need to see 3D are images from two perspectives, and your eyes and brain. I’ve mentioned these images before, here, with a link to some nice photographs using the same technique. Today while making some figures, I decided to do this with my very-high-resolution model of the right-ventricular free wall. I think it turned out pretty well.

You’ll want to click on the image and look at the full size rather than using the thumbnail. There’s a really large version that you can download and try here. The idea is just to cross your eyes and make the images line up. Sometimes it helps if you sit back from the computer a bit.

Note, this requires doing the opposite thing with your eyes compared with how you view a random dot stereogram.