I'm pretty sure that it is because of this mod, but I just have a night vision effect and I cannot turn it off.

There's a keybind for toggling the Night Vision effect, by default it's H
You can also change the keybind in the default minecraft keybindings menu

That's good to hear, thank you for the update.
I'll close this issue now then

Did you manage to turn off Night Vision or did the keybind not work?

Yes, sorry. I turned it off. I didn't see the keybind the first time. Sorry for the trouble.