Sunglasses

Sunglasses (or shades as they’re colloquially called) aren’t only worn to look cool. They provide comfort by protecting the eyes from bright sunlight—and also guard against the risks associated with UV light. Here’s a quick guide to choosing a pair of shades that will suit your needs.

Frame Material

Any pair of sunglasses are divided into two main parts: the lens that go over the eyes and the surrounding frame that keeps them in place. Sunglasses are made from a wide variety of materials, ranging from the cheapest plastic to expensive alloys with fancy names.

For casual use, the choice of material is less important than the lens themselves (see below). Frame material only matters in terms of comfort, and if you will use the sunglasses in physically demanding activities like sports and outdoors. In that case, get a frame that won’t break or shatter against hard impacts. You wouldn’t want to get pieces of the frame or the lens into your eyes, would you?

Many manufacturers highlight the frame material to justify the selling price. Look beyond the marketing and opt for a frame that’s strong enough for the planned activity. But more importantly get a frame that’s a comfortable fit on your head.

If possible, look for the sunglasses at a nearby store before saving money by buying it online. You should also look out for fakes: many customers have been duped by unscrupulous sellers who advertise a pair as the real deal but is actually a cheap knock off.

Lens Material

Most sunglasses use lens that are one of the four: Good ol’ glass, NXT polyurethane, Polycarbonate, and Acrylic.

Glass is the original material, used in sunglasses way before manufacturers thought of using the other three. It’s still the most scratch-resistant and offers the most image clarity. The drawbacks: glass is heavier than the newer materials, and makes up a large part of the production cost (i.e., it’s expensive). And of course, glass breaks.

NXT polyurethane on the other hand is the strongest material in the lineup, resisting impacts that would easily shatter glass. While also expensive, it has comparable clarity, is lightweight, and flexible. 
Polycarbonate lens are also strong, but not on the same level as NXT, and feature clarity inferior to that material and glass. However, they’re lightweight and cost less to produce. In short, polycarbonates offer good quality at lower prices.

Acrylic is the cheapest of the bunch, making them the most suitable for occasional sunglasses wearers. But you get what you pay for, ending up lens that easily break and actually distort the image, relative to the other three materials above.

When choosing among the four, keep in mind that higher quality necessarily results in higher prices. Acrylic is the best option for those who won’t wear sunglasses that often, and wear them in casual settings.

Regardless of what lens material you choose, look at the lens’ Ultraviolet (UV) protection and Visible Light Transmission (VLT) ratings. 100% UV protection is standard, and you shouldn’t buy shades that offer less than that.

VLT represents how much light gets through, and is dependent on the lens’ color and thickness. A VLT between 15%-25% provides a good mix of protection and visibility, and should be the only type used for activities like driving, as lenses with lower VLTs (such as those in glacier sunglasses) are only for specialized applications.

Lens Features

You should also consider what a pair of sunglasses offer beyond the frame and lens material.

Many sunglasses feature lens that have one or several layers of coating, to make the lens more versatile. Popular coatings include “hydrophobic” coating that repels water, and anti-fog layer that’s usually found on sports and outdoor sunglasses, and anti-scratch coating for added durability.

Another notable feature is interchangeable lenses, which allow the use of different kinds of lens with the same frame. This should appeal to those who need shades that are suitable for a variety of situations, but don’t want to spend on multiple pairs.