I could've sworn there was night vision in this game.
Apart from Cat Eyes, that drug, to make you see in the dark.

Is that the only form of night vision? I could've sworn the NCR Ranger helmet provided you with some type of Night vision, something like cat eyes, but it would be red and last until you turned it off. It was a shame really, to have only one form?
Can anyone confirm this?

Well there is a perk, and night scope mods

There is a perk that gives you night vision early on, as well as weapon mods like the night vision scope for the Varmint Rifle that give you night vision.

I thought I read that the Ranger helmet gives you night vision like the perk, I.E. slightly brightening everything at night, but then again, I could have been reading about a mod. Plus I had the perk when I got the helmet so i couldn't tell you.