How can edge thickness be reduced in high myopia?

High-minus lenses are thin in the center and become thicker toward the edge. The finished result therefore depends heavily on how far the frame extends from the optical reference point.

The most effective approach is to manage geometry first, then choose material, lens design and edging details.

01 · EFFECTIVE DIAMETER

The farthest point of the shape matters

A small A size alone does not guarantee a thin finished lens. The important geometric quantity is how far the most distant point of the frame lies from the optical reference point.

Square outer corners and oversized shapes can keep substantially thicker peripheral lens material than a compact round shape with a similar nominal width.

02 · EYE POSITION

Keep the eyes reasonably centered within the frame

When the pupil sits far from the frame’s geometric center, greater decentration and a larger blank may be needed. Even a small frame can perform poorly if a wide bridge pushes the eye far inward relative to the lens shape.

For high myopia, evaluate frame size and the wearer’s actual eye position together rather than shopping by the printed eye size alone.

03 · REFRACTIVE INDEX

Higher index can help, but it is one variable

A higher-index material can reduce thickness under the same prescription and geometric conditions, but index is not a quality grade. Abbe value, density, processing behavior and available coatings also differ by material.

A change from 1.67 to 1.74 may contribute less than reducing frame size or decentration in some cases. Geometry and material should be optimized together.

04 · LENS DESIGN & MINIMUM THICKNESS

The center cannot be made infinitely thin

Lens products and materials require a practical minimum center thickness, and base curve and design also affect the final form. Aspheric or other designs can optimize shape and off-axis optics but do not erase the edge-thickness problem by themselves.

The design goal is a stable, manufacturable lens—not simply the lowest possible center-thickness number.

05 · EDGE APPEARANCE

Finishing changes appearance more than physical thickness

Bevel placement and edge finishing can change how much edge is visible through the frame, but they do not remove the actual thickness. Polishing is not automatically better; in some lenses it can make internal reflections or edge rings more noticeable.

Frame color, eyewire thickness and the final mounting position should be considered together when judging cosmetics.

06 · ORDER OF DECISIONS

Solve the largest variables first

A practical order is frame size and shape → eye position and decentration → required blank diameter → material and design → bevel and edge finish.

Managing the geometry early often produces a larger improvement than trying to solve an oversized frame later with a higher-index material alone.

SOLUTION GUIDE

A practical high-myopia sequence

GLANOS LENS CHECK

For high myopia, frame selection is part of lens design.

Start with geometry; use high index as one tool rather than the entire strategy.

CAUTION

Choosing 1.74 does not automatically solve every edge-thickness problem.

GLANOS EYEWEAR

Eyewear discomfort has a reason.