Materials glossary / Lens material
Category 3 lens
On the label: Category 3 lens · Lens material
What it is
The common sunglass darkness (8 to 18 percent of light passes); category 4 is for glacier and sea use and is not legal for driving.
Lens materials: What a lens is made of decides its weight, clarity, impact resistance and how it takes a coating; UV blocking is a property of the material and its additives, not the tint.
In the research
No PubMed papers mention this material with jewelry, allergy or eyewear; that is usual for findings and trade terms.
Other lens materials
Clasp & Lens describes materials from the public record and does not appraise, grade or test pieces; what a listing states is the supplier's statement. If a piece causes a rash, take it off; a reaction that spreads or blisters is a doctor's question, and sunglasses are no substitute for impact-rated eye protection where that is required.