Materials glossary / Lens coating
Scratch-resistant hard coat
On the label: Hard coat · Lens coating
What it is
A clear hardened layer on plastic lenses; makes them scratch less, not scratch-proof.
Lens coatings: Layers applied to a lens: anti-reflective, mirror, polarizing film, photochromic dye, scratch-resistant hard coat.
In the research
1 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Effect of Ultraviolet Exposure on Impact Resistance of Ophthalmic Lenses · Optometry and vision science : official publication of the American Academy of O, 2015
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 coatings
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.