# Buyer guides

- [Polarized vs non-polarized lenses for sports: which one should your range carry?](https://www.sports-eye-wear-factory.com/blog/polarized-vs-non-polarized-sports-sunglasses/): When polarized lenses help athletes, when they hurt, and how to split a private-label sports sunglasses range between polarized, non-polarized and photochromic options.
- [Lens tint and VLT guide: filter categories 0–4 explained for sports eyewear](https://www.sports-eye-wear-factory.com/blog/lens-tint-vlt-guide-filter-categories/): What visible light transmission (VLT) means, how ISO 12312-1 filter categories 0 to 4 are defined, and which tints suit cycling, running, fishing, ball sports and snow.
- [TR90 vs PC vs TPU vs metal: choosing frame materials for sports sunglasses](https://www.sports-eye-wear-factory.com/blog/tr90-vs-pc-vs-tpu-sports-frame-materials/): A practical comparison of TR90, polycarbonate, TPU, metal and acetate frames for sports eyewear, including weight, flexibility, cost, colours and best uses.
- [Sunglasses compliance for importers: UV400, ISO 12312-1, ANSI Z80.3 and FDA impact rules](https://www.sports-eye-wear-factory.com/blog/sunglasses-standards-uv400-iso-12312-ansi-fda/): The standards and tests importers of sports sunglasses usually need for the EU, UK, US and Australia, plus impact standards for tactical and racquet-sport eyewear.
- [How private-label sports sunglasses are made: MOQ, logos, packaging and lead times](https://www.sports-eye-wear-factory.com/blog/private-label-sports-sunglasses-oem-guide/): A step-by-step guide to launching a private-label sports sunglasses line with a factory: minimum order quantities, logo methods, lens and colour options, packaging and typical timelines.
- [Ski goggle lens guide: cylindrical, spherical, toric and magnetic systems](https://www.sports-eye-wear-factory.com/blog/ski-goggle-lens-guide-cylindrical-spherical-magnetic/): How cylindrical, spherical and toric ski goggle lenses differ, how magnetic quick-change systems work, and which anti-fog, OTG and strap options to specify for a private-label snow range.
- [Pickleball sunglasses: what players need and how to spec a private-label pair](https://www.sports-eye-wear-factory.com/blog/pickleball-sunglasses-buyers-guide/): Why pickleball players wear eye protection, which frame shapes and lens tints help ball tracking, and what to specify when you develop branded pickleball sunglasses for clubs and retailers.
- [How to choose a sports sunglasses manufacturer in China: a buyer’s checklist](https://www.sports-eye-wear-factory.com/blog/how-to-choose-sports-sunglasses-manufacturer/): A practical checklist for vetting a sports eyewear supplier: moulds, sampling, quality control, compliance documents, communication and payment terms.