[walterbell]

Nikon has a joint venture with Essilor (soon to be Luxottica), so their lenses are very similar: https://www.essilor.com/en/medias/news/nikon-essilor-15-year... & https://www.optiboard.com/forums/showthread.php/56186-Nikon-...

Here is a chart on lens materials: http://64.50.176.246/tools/materials.php