"lunettes" are "glasses" in French and Lunetta just reminds me of the word. It isn't appealing and neither is Julina. They both seem made up. As if you liked
Luna and
Julia but desperately wanted something less common.
Instead I'd suggest names that don't seem so contrived such as
Juliet,
Juliette,
Lyra,
Lana or
Juliana.
However, the names aren't awful. So if you like them, go for them :)