Night-vision devices that amplify ambient light using image-intensifier tubes may fall here if they function as optical telescopes or binoculars, but many night-vision and thermal-imaging instruments classify under the heading for instruments using infrared or electronic imaging rather than purely optical means. The operating principle — passive optical versus electronic detection — is the key classification factor, and a binding ruling is advisable for hybrid devices.

High-performance optical instruments, particularly those with military-grade specifications, may be subject to Export Administration Regulations (EAR) or International Traffic in Arms Regulations (ITAR) controls on export. Importers reselling or re-exporting such instruments should verify the Export Control Classification Number (ECCN) and any applicable license requirements before shipment.