The technique gives an illusion of 3D by showing two images in rapid alternation: one from a left eye, and one from a right-eye perspective. Essentially it is separating the two pictures in time instead of space as is normally the case. You don’t need to wear special glasses to see the effect, and the illusion of dimensionality can be quite striking.

For those of you interested in trying their hand at making stereoscopic pictures, check out this awesome tutorial that teaches how you can create them using 2 photos and a few lines of Javascript code.