Eyewear falls under three customs headings: 9001 for lenses (contact lenses 9001.30, spectacle lenses 9001.40 glass and 9001.50 other), 9003 for frames and mountings (9003.11 plastic, 9003.19 other, 9003.90 parts) and 9004 for spectacles, goggles and sunglasses (9004.10 sunglasses, 9004.90 other). Duty rates differ by heading and origin; check the tariff for your market.
Regulatory requirements sit on top of duty. Sunglasses need CE (EN ISO 12312-1) in Europe and must meet ANSI Z80.3 in the United States and AS/NZS 1067 in Australia; safety eyewear needs certification to EN 166 or ANSI Z87.1; contact lenses and solutions are medical devices needing FDA, CE MDR or national registration. In India, BIS standards apply to certain optical products and imports of spectacle frames and sunglasses carry customs duty plus GST.
Ask suppliers for test reports, declarations of conformity and, for medical devices, the regulatory file. Customs may also ask for material declarations, nickel-release test results for metal frames and, for children's products, chemical compliance.