Eyewear Guide

It is time to update your glasses prescription when your vision changes, when your glasses no longer feel comfortable for everyday tasks, or when your optometrist...

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...

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...

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...