I struggled at the beginning and was almost certain I was one of the small percentage who can't see them, but after working on it for a while I managed to see them. Now I use them to relax my eyes with the parallel mode. I remember not being able to properly align the two images on a stereo microscope without pulling outward one of my eyelids (which in turn adjusts one eye). I did the same for the magic eye until I was able to see the stereoscopic image form, then I no longer needed to do that.