Relax your eyes until you see a fourth image appear. Depending on whether  you  cross or separate your eyes, one of the two images in the middle will be the correct 3D image and the other middle image will be the opposite direction 3D.

3D Transmitted Light
 Fluorescence image of a blood vessel from a 30µ thick preparation of kidney, stained with hematoxylin & eosin. Mag. 100x.

     

3D Transmitted Light 
Triple band pass fluorescence image of cells grown in vitro. Note, even in a thin preparation, 3D reveals interlacing structures. Mag. 500x. (Preparation courtesy of Molecular Probes, Inc. Photomicrography by Dr. Gary L. Greenberg)

3D Transmitted Light
Fluorescence image of 40µ thick section pig intestine, stained with hematoxylin & eosin. The eosin is auto-fluorescent. Mag. 50x.