You’ve seen it written on shades at your local opticians. Maybe even heard it uttered by goggle-tanned French skiers in Alpine lodges. But for the vast majority of us, the word “polarised” is something of an enigma. A mystery word whose presence seems to do nothing more than command drastically higher prices than for your average pair of sunglasses.

But does that mean polarised sunglasses are nothing more than a swizz? A pointless luxury that people with surplus cash can purchase to give them a feeling of superiority?

Well, no. In actual fact, polarised lenses are well worth the money. But not necessarily for everyone. “A lot of people know the word ‘polarised,’” says Craig Smith, European sales manager for eyewear brand Dragon Alliance. “However, understanding what it does to light passing through a sunglass lens will help you decide if this additional, premium feature is for you.” Polarised lenses filter light in a unique and useful way. However, to understand how they work, you first need to understand glare.

The Glaring Issue

If you’ve ever struggled to read your phone screen or make out a license plate due to sunlight, then you’ve experienced glare. At risk of getting all sciency, this is what happens with light hits a flat or uneven surface and is reflected horizontally. This reflected light can be extremely bright and cause difficulty seeing.

This can cause significant issues for people whose hobbies or work require them to see clearly in places where glare is rife, such as at sea or on snow-covered mountains, or even just driving in the summer. And polarised sunglasses can provide the solution. But how do they do it?

Polarised vs Non-Polarised Sunglasses?

In 1929, Edwin Land invented Polaroid, the world’s first polarising material for commercial use. His company’s Polaroid Day Glasses became the first ever polarised sunglasses, offering customers a way of reducing light without simply darkening the landscape.