Lens Guides - LensPT

Spherical vs. Aspheric Lenses: A Design Comparison for Optical Buyers

Blue-reflective resin single-vision lens, product view 1

Separate surface design from refractive index, coatings and processing scope. Compare spherical and aspheric lenses using identifiable designs and consistent sample records.

1.61 vs. 1.67 vs. 1.74 Lenses: A Sourcing Guide for Optical Buyers

Clear single-vision ophthalmic lens, product view 1

Compare 1.61, 1.67 and 1.74 lenses by material identity, finished geometry and order scope. Use a consistent comparison record before approving an index change.

HC vs. HMC vs. SHMC Lens Coatings: A Buyer’s Specification Guide

Concept illustration of spectacle lenses for a comparison of HC, HMC and SHMC coating specifications.

Understand hard coating, anti-reflective treatment and hydrophobic finishes, then compare coating packages with a practical buyer specification record.

Photochromic vs. Polarized Lenses: A Sourcing Guide for Optical Buyers

Concept illustration of clear and gray spectacle lenses for a photochromic versus polarized lens comparison.

Compare light adaptation and reflected-glare control, check the evidence for each lens configuration, and prepare a focused sourcing inquiry.

Round-Top Bifocal Lenses vs. Flat-Top: A B2B Design Comparison

Concept diagram comparing the rounded near segment of a round-top bifocal lens with the straight upper edge of a flat-top bifocal segment.

By LensPT Team Round-top bifocal lenses have a rounded near segment; flat-top bifocal lenses have a near segment with a straight upper edge. These names describe the segment inside the lens, not the shape of the uncut lens blank or the finished frame. For optical distributors and purchasing teams, the useful comparison starts with the […]

Blue Cut Progressive Photo Gray Lenses: How the Three Features Work Together

Concept illustration of a progressive lens showing distance, intermediate and near vision zones.

By LensPT Team Published 2026-10-07 Blue cut progressive photo gray lenses combine three features: a progressive optical design, blue-light filtering, and a gray photochromic tint. These features describe different aspects of the lens. The progressive design provides different viewing zones, the blue-cut feature changes the transmission of selected wavelengths, and the photochromic treatment […]