Guides

• How to Read Temple Size Markings (Markdown)
  What the three numbers in a marking such as 52-18-140 mean, where they usually appear, and why a size alone cannot identify a model.
• Comparing Frame Sizes Dimension by Dimension (Markdown)
  How to compare lens, bridge, temple and frame width in mm, why frame width is not 2 × lens + bridge, and what the numbers leave out.
• Polarized Lenses in the Data (Markdown)
  What the polarized field means in this catalog, why unknown is not false, and why polarization and UV statements are kept apart.
• Maker Bridge Fit Labels Explained (Markdown)
  How Ray-Ban, Oakley and Maui Jim fit labels map to this catalog's bridge_fit values, using only each maker's own published definitions.
• Lens Specifications in the Catalog (Markdown)
  How this catalog records light transmission, lens category, lens material and UV statements as cited maker claims rather than test results.
• Data Scope, Sources and Freshness (Markdown)
  What this sunglasses catalog covers, what each field_status means, which sources it cites, and how check times and freshness work.