Ghostbusters Ecto Goggles

For a friend's birthday i wanted to build some ecto-goggles, because he is a big fan of Ghostbusters. I found some welding goggles at our hardwarestore and remembered some pictures of some DIY-Ectogoggles based on this model. You can find it by the following names:
Forney 55320 Goggles
AES Industries Welding Helmet Style Flip-up Goggles
Hobart 770094 Welding Oxy-Acetylene Goggle

I know they are not very accurate to the one in the movie, but it will work for my purposes.

The biggest prob