The depth you see is the depth you hear.
Instructions: Listen with headphones, otherwise you won’t hear it. Fuse the stereogram by crossing or relaxing your eyes until the sphere in your left eye overlaps the sphere in your right eye. I find it easier to fuse stereograms by crossing my eyes, but some people find it easier to relax them. Stretch your eyes here, if you’d like to practice first, or see the tutorial here.
