Materials glossary / Frame material
Keyhole bridge
On the label: Keyhole bridge · Frame material
What it is
A bridge shaped like a keyhole that rests on the sides of the nose; suits narrow or low bridges.
Frame materials: Frame materials: acetate, injection-molded plastics, metals and the memory alloys; weight, flex, allergy and repairability follow from the material.
In the research
No PubMed papers mention this material with jewelry, allergy or eyewear; that is usual for findings and trade terms.
Other frame 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.