Sunglasses Guide

The easiest way to buy sunglasses online is to compare the measurements with a pair that already fits. Start with size and bridge fit, then choose the shape and lens features you prefer.

1. Read the size

Cosmoshop displays eyewear sizing as 54.20/140, in millimetres:

Number	Measurement	What it affects
54	Lens width	The horizontal width of one lens.
20	Bridge width	How the frame sits on your nose and whether it slides or pinches.
140	Temple length	How the arms sit behind your ears.

A current pair that fits is the best reference. Similar printed measurements are useful, but total frame width, hinge design and shape can still change the fit.

2. Check the fit

The frame width should broadly follow the width of your face.
The bridge should feel secure without pinching or constant sliding.
Your eyes should sit reasonably close to the centre of the lenses.
The lower rim should not press into your cheeks or lift when you smile.
The temple arms should feel secure without squeezing your head.
Your eyelashes should not brush the lenses during normal blinking.

Adjustable nose pads give more fitting flexibility. Fixed acetate or plastic bridges need a closer natural match to your nose shape.

3. Choose shape and coverage

Face-shape suggestions are only a starting point. Fit and personal preference matter more.

Round: angular, rectangular or browline frames can add definition.
Square: round, oval or softly curved frames can soften stronger angles.
Oval: most shapes can work; focus on width and proportion.
Heart-shaped: aviator, oval and lighter lower-rim styles can balance proportions.

4. Choose lens features

UV protection: darkness alone does not prove UV protection. Check the product specification.
Polarised: reduces reflected glare from roads, water and other flat surfaces.
Gradient: darker at the top and lighter below; useful for some city and dashboard use.

Lens colour	Typical effect
Grey	Neutral colour perception for versatile everyday use.
Brown / amber	Warmer appearance and increased perceived contrast.
Green	Balanced colour rendering with good general contrast.
Mirror finish	Reflective appearance and additional visible-light reduction; performance varies by lens.

Before ordering

Compare the 54.20/140-style measurements with a pair that fits.
Check total frame width, bridge design, cheek and eyelash clearance.
Choose the lens coverage and shape you want.
Confirm the UV protection and whether polarisation, gradient tint or mirror coating is useful.
Check the case, accessories, warranty and return information.