Stereoscopy is a technique where the illusion of depth is artificially created: slightly different images are presented to the left eye and right eye. 3d glasses merge these two separate images, so that your brain can process them as a single (seemingly) 3d image.

Without 3d glasses on, things start to look a bit…dizzying. Here are some striking examples of stereoscopic photography.

1. Sophie, the hot dog. By jimf0390.

1. This dress might be sold out, but we can still dream about it.

3. Stereoscopic 3D, by Trypode. (Robots and unicorns! Weehee!)

4. 3D Anaglyph red cyan glasses, by 3d Stereopics

5.  Lake shore walk, by jimf0390

Here’s a tutorial on how to make your won stereoscopic images.