9002 - Lenses, prisms, mirrors and other optical elements, of any material, mounted, being parts of or fittings for instruments or apparatus, other than such elements of glass not optically worked; parts and accessories thereof:

This HTS chapter (Section XVIII, Chapter 90) pertains to sophisticated instruments and apparatus, encompassing optical, photographic, cinematographic, measuring, checking, precision, and medical/surgical devices, along with their associated parts and accessories. It is crucial to understand that Chapter 90's scope is specifically for these specialized instruments and does not cover basic optical components made of glass that are not optically worked or mounted for use in these devices.

Within this broad chapter, heading 9002 specifically covers lenses, prisms, mirrors, and other optical elements that are mounted and intended for use as parts or fittings within instruments or apparatus. This heading is distinct from unrelated chapters covering raw materials, basic optical components not integrated into an instrument, or finished optical goods not serving as part of a larger apparatus. For instance, raw glass for optical use would fall under Chapter 70, while finished eyeglasses for vision correction would likely be classified elsewhere.

Heading 9002 is further subdivided to refine classification based on the specific type of optical element and its function. The subcategories address objective lenses (commonly found in cameras, microscopes, and telescopes), filters designed to modify light, and a residual "other" category for various mounted optical elements not otherwise specified. This hierarchical structure allows for precise tariff identification of specialized optical components based on their form and intended application within instruments.