Talking about insulting: Yes it is a cuss word, but let's go to the terminology: Nudel is noodle and Auge is eye. Doesn't fit together you think? Think again, we are talking about Austrians :)
As we are talking about where the word comes from, this word was made super-popular by the series "Ein echter Wiener geht nicht unter" staring Karl Merkatz as Edmund "Mundl" Sackbauer.
But I still owe you the complete root of the word: Nudel as noodle is not referenced to spaghettis the singular form is more fitting and then only if you use it in the context of part of the male reproductional system. But then you might wonder what an eye has to do with that... If you are still wondering, you might have to watch more movies!