Wait wait wait. You’ve got a goal to 3D optical lenses? Nice!
I’d probably start with a resin 3D printer though. It’s seems the precision would be beneficial for an optical lenses?
I don’t know about any clear resins though. I don’t have a resin printer. It’s a very PPE oriented printing process, that didn’t suit when I tried it.
Okay fluoride gang (of which I may be a member)…
A study about the affects of fluoride in municipal water on plants: MSU study