Eyewear Care & Ultrasonic Cleaning
Cleaning Sunglasses with Polarized or Mirrored Lenses Correctly
Polarizing and mirror coatings sit as an ultra-thin extra layer on the lens and are especially prone to scratches and peeling if cleaned incorrectly. Contact-free ultrasonic cleaning is the safest method here.
What polarization and mirroring actually are
A polarizing layer filters out horizontally reflected glare (e.g. from water or asphalt). A mirror coating is an additional, very thin metallic vapour-deposited layer on the lens surface that reflects part of the light. Both layers sit on top of the actual glass or plastic lens.
Why these coatings are more sensitive
Since both layers are applied on top, they're often thinner and more sensitive than the base material itself. Dry wiping or abrasive cleaning agents can visibly wear away the mirror coating or leave it looking patchy – damage that can't be undone.
Why ultrasonic cleaning is safe here
Since nothing rubs against the lens during cavitation (see What is an ultrasonic cleaner and how does cavitation work?), the sensitive coating stays untouched. For NURO, that explicitly includes polarized and mirrored sports sunglass lenses.
Author: Moritz Weinert, Gründer NURO Labs · Last updated on 8 September 2026