Eyewear Guide

Pupillary distance, usually shortened to PD, is the distance between the centres of your two pupils, measured in millimetres. It tells the lens maker exactly where...

Your glasses prescription is a short code that tells a lens maker exactly how to correct your vision. It lists numbers for each eye, such as...

Sunglasses lenses come in different tint colours and darkness levels, and each one changes how you see the world. Grey keeps colours natural, brown boosts contrast,...

Polarised sunglasses have a special filter that blocks the harsh, flat glare reflecting off water, wet roads, snow and car bonnets. Non-polarised sunglasses reduce overall brightness...

Photochromic lenses, often called Transitions after a well-known brand, are clear indoors and darken automatically when exposed to UV light outdoors. They let one pair of...

An anti-reflective coating is a very thin layer on your lenses that cuts down the reflections bouncing off the front and back surfaces. It lets more...

Lens materials decide how thick, light and tough your glasses will be. The main options are CR-39 plastic, polycarbonate, Trivex and high-index plastics (1.6, 1.67 and...

Single vision lenses have one prescription across the whole lens, for either distance or reading. Bifocal lenses have two zones, usually distance on top and reading...

Full-rim glasses have a frame all the way round each lens, semi-rimless glasses have a rim on the top only, and rimless glasses have no rim...

Glasses should sit level on your face, rest comfortably on your nose, hold gently behind your ears and stay in place when you look down. Your...

Eyewear comes with a lot of jargon. This A to Z glossary explains more than 40 common terms for frames, lenses, sunglasses and prescriptions in plain...

Glasses frames are mostly made from plastics such as acetate, injected plastic and TR90, or metals such as stainless steel, titanium and beta-titanium, with wood as...