Sunglasses | Optical Centre Smartbuyglasess UK

Photochromic or Polarised Sunglasses?

As summer officially begins (in the Northern Hemisphere at least), you may be thinking about spending some more time outside. With such a wide range of sunglasses available, it’s definitely worth thinking about getting some specialised sunglasses for long afternoons in the sun. If you’ve been shopping around, you may have noticed some phrases - ‘polarised, photochromic’ - popping up every so often without knowing what they actually mean. 

This brief guide aims to clear up the difference between photochromic and polarised sunglasses, as well as explaining how they actually work.

What Does ‘Polarised Sunglasses’ Mean and How Do Polarised Lenses Work?

Sunlight scatters in all directions, but when it strikes flat surfaces, the light that is reflected by the surfaces tends to become polarised - meaning the beams of light bounce off and travel in straight lines. This creates an annoying (and occasionally dangerous) intensity of light that causes glare and can reduce visibility.

Polarised lenses have a special filter that blocks this type of intense reflected light, reducing glare and boosting your visibility on bright days. This comes in handy in situations like being around water and snow - both reflect a lot of light, which can really damage your eyes if you’re not careful. This has a practical use as well - fishermen often wear polarised fishing sunglasses to reduce glare and spot fish under the water’s surface.

In the same way that you’d wear sunscreen to protect your skin, it makes a lot of sense to wear polarised sunglasses to protect your eyes. If you’re interested in discovering a huge range of polarised shades, browse a large range here.

What Are Photochromic Lenses?

Photochromic lenses contain a special chemical which darkens on exposure to sunlight and protects the eyes from ultraviolet radiation. Unlike regular or polarised sunglasses, photochromic sunglasses change colour according to the brightness of the local area - whether that’s outside, or even in a room with bright lights. For example, walking outside from a dark room on a sunny day would cause your photochromic lenses to darken from normal-looking glasses to sunglasses. You can see our range of photochromic, also known as transition, sunglasses here.

Why Wear Prescription Photochromics?

Photochromic lenses offer great flexibility to anyone needing prescription eyewear, protecting the eyes indoors and out at all times. It’s also worth noting you can buy sunglasses with photochromic and polarised lenses.

Who Wears Photochromic Lenses?

Photochromics are versatile enough to suit anyone, on nearly any occasion. For outdoor sports enthusiasts, where good vision is as important as comfort and protection (think cycling, skiing or golf), or students switching from the lecture hall to the playing field, photochromic lenses ensure your eyes are protected whenever.

Photochromic vs Polarised Lenses?

So, to clear up - the big difference between photochromic and polarised lenses is:

  • Polarised lenses are always tinted dark - they don’t change colour. Polarised lenses reduce glare wherever they can: on bright, horizontal surfaces, such as white sand beaches, snow, and sunlight reflecting off water.

  • Photochromic lenses, on the other hand, are usually clear but turn dark in bright sunlight. Then, when you go back somewhere dimmer, they become clear once more.

If you’re interested in the different types of lenses out there and want to read more, try our guide to choosing the best sunglass lenses.

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