The fact is that most glass for optics are manufactured in Japan and have for decades, including Swarvoski, Zeiss, and Leica. The Germans don't make their glass it the Japanese who make it for them. Quality of glass depends on quality and quanity of polishing. I'm assuming that the Vortex glass is made in Japan as well. Japan has made some of the best cameras in the world, case in point I just purchased a FujiFilm camera recently and compared it to a Canon of equal value and design and the Fujifilm won hands down! Japan has made many great products, hell they even make the best vehicles in the world which include Honda and Toyota. I feel sorry for those people what they are going through now.
sorry but lenses (this is the name for glass optics) are still made in Europe not only the polishing (not only in Europe) and by many operators :
Zeiss (Germany, Japan, Hungary, Czech Republic),
Docter ex-karl zeiss jena (Germany),
Swarovski (Austria, Japan)
Kahles (Austria) is still making lenses and not only for them ...,
Schmidt und Bender (Germany, Hungary)
Meopta (Czech Republic, Japan)
IOR (Romania)
Kaps, Gerhardt, Nickel (Germany)
and i certainly forget some other very little companies ....
cant comment for Leica riflescopes but pretty sure its Japan as it was for the Leupold Leica before ... but some of the optics for camera are coming from germany.
if you have a little time you ll discover that Schott Glasses is making lenses for many optic builders ... they re made in Mayenz ... and the big ones are still buying there ..