What Are Polarized Sunglasses? A Complete Guide
Learn how polarized sunglass lenses filter horizontal glare, their benefits and limits, and what to check when sourcing polarized lenses.
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The Buyer's Guide.
Practical articles on lens materials, coatings, sourcing and private label — written to help you spec better eyewear and buy smarter.
Welcome to the SunDefeat knowledge base. These guides are written for brand owners, distributors and retailers who buy eyewear at volume — not for end consumers. Each article focuses on the decisions that affect your cost, quality and margin.
Lenses
Lenses
Photochromic Lenses Explained: How Light-Adaptive Lenses Work
How photochromic lenses darken in sunlight and clear indoors, key materials and activation factors, plus what wholesale buyers should evaluate.
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Lenses
Sunglass Lens Materials Guide: Polycarbonate, Nylon, Glass & Resin
Compare polycarbonate, nylon, glass and resin sunglass lens materials on clarity, weight, impact resistance and cost for your product line.
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Lenses
Lens Coatings Guide: UV400, Anti-Scratch, Anti-Fog & Waterproof
A buyer’s guide to UV400, anti-scratch, anti-fog and waterproof lens coatings, and how to combine them for durable performance eyewear.
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Lenses
Sunglass Lens Color Guide: G15, Grey, Brown, Green & Gradient
How grey, G15, brown, green and gradient lens tints affect color, contrast and glare, and how to choose tints for your sunglass range.
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Sunglasses
Sunglasses UV Protection Guide: UVA, UVB and UV400
Learn how UVA, UVB and UV400 protection works in sunglasses lenses, plus manufacturing and customization options for wholesale buyers.
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Sunglasses
Types of Sunglasses: A Guide to Shapes, Lenses and Functions
Explore sunglass frame shapes, lens types and functions, plus how manufacturers customize frames and lenses for wholesale product ranges.
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Sunglasses
Gradient Sunglasses Guide: How Gradient Lenses Work
Learn how gradient sunglass lenses are tinted, how they compare to solid tints, and the customization options available for wholesale buyers.
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Sunglasses
Cheap vs Expensive Sunglasses: What Actually Makes the Difference
Understand what separates cheap and expensive sunglasses — materials, lenses and finishing — and how to choose the right tier for your market.
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Frames
Eyeglass Hinge Types Guide: Spring, Barrel and Hidden Hinges
Compare spring, barrel and hidden eyeglass hinges, their mechanics, materials and manufacturing cost drivers to specify the right hinge for your frame collection.
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Frames
How to Measure Eyeglass Frame Size: Lens, Bridge and Temple
Learn the boxing system for eyeglass frame measurement — lens width, bridge width and temple length — and how to specify accurate sizes for production.
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Frames
How to Clean Eyeglasses and Sunglasses Properly
A practical guide to cleaning eyeglasses and sunglasses without damaging lenses or coatings, plus care guidance for eyewear brands and distributors.
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Frames
Why Do Glasses Fog Up? Causes and Anti-Fog Solutions
Understand the condensation science behind fogged lenses and compare anti-fog coatings, sprays and ventilation for eyewear manufacturing.
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Style
Cat Eye Glasses & Sunglasses: A Style Guide
A cat eye glasses and sunglasses styling guide for eyewear brands: face shape fit, custom manufacturing options, and materials and colors.
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Style
Clear & Transparent Frames: A Modern Eyewear Guide
A clear and transparent frames guide for eyewear brands: transparent frame trends, face shape fit, anti-yellowing materials and custom color options.
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Style
Round & Circle Glasses: A Timeless Style Guide
A round and circle glasses styling guide for eyewear brands: timeless round frame appeal, face shape fit, and custom materials and colors.
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Industry
Who Invented Glasses? A Brief History of Eyewear
Who invented glasses? A brief history of eyewear from medieval reading stones to modern sunglasses and custom frame manufacturing.
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Industry
How to Choose a Sunglasses Manufacturer: A Buyer's Guide
How to choose a sunglasses manufacturer: evaluate production capacity, quality control, MOQ, lead times, certifications and customization.
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Frames
How to Clean & Care for Your Sunglasses
Learn how to clean and store sunglasses so frames last for years, with material-specific care tips that help brands reduce returns.
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Frames
How to Measure Your Face to Find Your Sunglasses Size
Measure face width and understand lens, bridge and temple dimensions to choose the right sunglass frame size for every face shape.
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