Materials glossary / Lens material
Glass (mineral) lens
On the label: Glass lens · Lens material
What it is
Crown glass: the clearest and most scratch-resistant lens, and the heaviest; it can shatter, so US glass lenses must be tempered to pass the FDA drop-ball test (21 CFR 801.410).
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
80 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Hybrid endomicroscopic objective with monolithic multi-material achromatic triplet fabricated using two-photon lithography · Applied optics, 2026
- Synovial fluid delays delamination wear in immature bovine cartilage under pure cyclical compressive loading without sliding · Osteoarthritis and cartilage, 2026
- A molding approach to fabricating meniscus cylindrical glass lenses for beam shaping · Optics letters, 2026
A paper is a paper, not a verdict: titles are listed so you can read them, and a study on one fabric or one filter says little about the piece in your hand.
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.