Glossary A–M

Speak fluent eyewear.

By James Stone

Issue #1 · Published Oct 19, 2026

Acetate: Plant-based plastic (cotton fibers, wood pulp) cut into sheets, then shaped, tumbled, and polished into frames.
Anti-reflective: A lens coating that cuts glare and ghost images. Also called AR.
Aspheric: A flatter, thinner lens design that reduces the bulge in strong prescriptions.
Base curve: The curvature of the lens front, matched to the frame's wrap.
Bifocal: A lens with two powers: distance up top, reading in a visible lower segment.
Bridge: The part that sits on your nose, connecting the two lens rims.
Cat-eye: A frame with upswept outer corners. The 2026 version: subtle, lifting, almost predatory.
Coating: A thin lens treatment: anti-scratch, anti-reflective, UV, or hydrophobic.
Cylinder: The lens power that corrects astigmatism. On your prescription as "CYL."
Diopter: The unit of lens power. Higher number, stronger correction.
High-index: Denser lens plastic that makes strong prescriptions thinner and lighter. Common: 1.67, 1.74.
Hinge: The joint where temple meets front. The smallest part doing the most work.
Lenticular: A lens ground thin at the edges with a central optical zone, for very strong prescriptions.
Monocle: One lens, one eye, zero temples. A vibe more than a vision plan.
Multifocal: Any lens with more than one power: bifocals, trifocals, progressives.