The dividing line is whether the optical element — lens, prism, mirror, or filter — has been mounted in a frame, housing, or other support. Unmounted elements classify here under 9001, while the same element once mounted for use in an instrument or apparatus moves to the heading covering mounted optical elements and their parts.

Yes. Contact lenses are regulated as medical devices by the FDA under the Federal Food, Drug, and Cosmetic Act. Imported contact lenses must come from FDA-registered establishments, and shipments are subject to FDA review at the port of entry. Importers should work with a licensed customs broker and confirm FDA registration and device listing before shipment.