When I stumbled upon the prop-replica 'net community a few years, my interest was largely bent on Ghostbuster props. Though I've started a proton pack and a trap, neither are anywhere near complete. The Ecto-goggles on the other hand were far easier to take a stab at, both in terms of skill and price.
My first try. The Testors olive drab paint I used on the welding goggles didn't take very well, unfortunately. It stayed tacky, and collected hair and dirt like a foul-smelling katamari. The lens-tubes are microscope elements. My shame mounts every time I see this photo.
My second attempt turned out much cleaner, thanks to the vinyl dye I used on the welding/brazing goggles. Black is inaccurate to the films of course, so these are closer to special ops goggles from any number of movies and games.
With both pairs of goggles, I attached a third strap which runs from the top-center of the goggles to the back of the existing headband. Without the additional strap, the goggles just sag/fall off your face. The labels were printed with my inkjet printer onto label paper from images hosted here, http://www.hprops.com/labels/KJH_MT500&ANPVS5.pdf
Neither pair of goggles is practical as far as costuming goes. The microscope elements look nice, but they're impossible to see through. I purchased some 'optical windows' from an optics site online that are just small enough to fit into some of the PVC plumbing bits referenced here, http://www.gbprops.com/plans/norm_goggles/ and I plan on using those in my next pair.
About the biggest problem I ran into working with the brazing goggles as a base was how flexible the rubber was. It won't support much weight without warping, and if you manage to twist the material enough (like I tended to do when installing the knobs and top strap) it never regains its original shape. Eventually I hope to get my hands on a real AN/PVS-5 frame so I can try for a movie-accurate pair. Prospective goggle-makers may also run into problems locating goggles shaped like these, at local home improvement stores. At least in my area, I've noticed that Lowe's and Home Depot both have been replacing the 'box' type goggles with something closer to motorcycle goggles.
Also, for those wanting to use vinyl dye for their own projects, keep in mind that it doesn't work on all types of plastics. For instance, the particular plastic used in the 1-1/4" insulating bushings used for the round 'mounts' at the base of each lens-tube do not take the dye at all. It simply flakes off to the touch once dry.