Here's a mystery. L.T. Piver is a French Perfumer. This bottle claims to have something to do with vinegar and eye repair. Seriously, what the heck is it???
This is something like a face lotion / toner. The vinegar is used to clarify the skins complexion. "Lait d'iris" is just the name of this specific cosmetic range. Link to a french website (picture 14)