Materials glossary / Frame material
Spring hinge
On the label: Spring hinge · Frame material
What it is
A hinge with a spring that lets the temples open beyond 90 degrees; forgiving for taking glasses on and off one-handed.
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.
Pieces whose listing names it
6 on the siteMatched from the words in the supplier's listing; the full material line is on each product page.
Made in the USA
Made in the USA
Made in the USA
Made in the USA
Made in the USA
Made in the USA
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.