Optical Frame Guide

Compare a frame that already fits, then consider bridge design, lens shape, material and prescription suitability. Your optometrist or dispensing optician should make the final lens-compatibility decision.

1. Read the frame size

Cosmoshop displays optical-frame sizing as 54.20/140. These numbers describe the frame, not your prescription.

Number	Measurement	What it means
54	Lens width	The widest horizontal point of one lens opening.
20	Bridge width	The space between the lenses and a key part of nose fit.
140	Temple length	The arm length from hinge to tip.

Printed size is only a starting point. Compare total frame width, lens height, shape and bridge construction as well.

2. Check the frame against your face

Your pupils should sit reasonably close to the centre of the lens openings.
The bridge should stay in place without constant adjustment.
The frame should sit level and the temples should not bow sharply outward.
The lower frame should not lift when you smile or rest heavily on your cheeks.
Temple ends should hold the frame comfortably behind your ears.

Adjustable nose pads allow more control over height, angle and weight distribution. Small professional adjustments after lens fitting are normal.

3. Confirm prescription suitability

Stronger prescriptions: smaller, rounder full-rim frames can often help reduce visible lens thickness and weight.
Progressive lenses: the frame needs enough vertical depth for the required fitting height.
Rimless / semi-rimless: not every lens material or prescription is suitable for exposed or drilled edges.

PD and fitting height are lens measurements. Do not estimate them from the 54.20/140 frame code. Have prescription lenses measured and fitted by a qualified optical professional.

4. Choose the frame material

Material	What to expect
Acetate	Substantial feel, rich colours and patterns, usually with a fixed bridge.
Stainless steel / metal	Slimmer construction and often adjustable nose pads.
Titanium	Lightweight and corrosion resistant; useful for all-day comfort.
Injected / nylon-based	Light and durable; adjustment methods vary by construction.

Remember that the finished lenses also add weight, especially with larger lenses or stronger prescriptions.

Before ordering

Compare the 54.20/140-style measurements with your current glasses.
Check frame width, bridge, temple length and lens height.
Confirm the frame suits your prescription and visual needs.
Check whether the bridge is fixed or uses adjustable nose pads.
Confirm your optical professional can fit the required lenses.
Check what is included, plus warranty and return information.