Copperfield’s Guide to Buying Sunglasses

Summer has finally come, time to hunt out those shorts, slather on some sun cream, and treat yourself to that new pair of sunglasses. But with so many styles to choose from, finding the right pair of sunglasses can be difficult, especially if you are buying online. Read our handy guide on what to look out for when buying sunglasses.

UV Protection

UV light from the sun can cause damage to the eyes, therefore a good pair of sunglasses are essential for protecting them. Most sunglasses offer 100% UV protection, but it is important to check as some cheaper options might not give you full protection.

Look out for the protection index for full peace of mind. The index grades lens filtering abilities from zero to four, this grade signifies the lens filtering abilities and indicates how much light a sunglass lens lets through – also known as visible light transmission (VLT).

Grade zero is a clear or lightly tinted lens with 80-100% VLT, whereas grade four is a very dark lens with only 3-8% VLT. If looking for a pair of sunglasses for everyday use a grade one to three is best.

Lens Treatment

Sunglasses tints

There are a variety of different lens treatments that can affect the look and level of protection the lens has.

Polarisation is the most common lens treatment, a polarised film is added to the actual lens. Polarised lenses block the glare from the sun, keeping your vision sharp and clear. Glare is also blocked that comes from snow, water, and car windows.

Photochromic lenses adapt depending on the intensity of the sunlight. Also known as transition lenses, these lenses darken in the sunlight or UV rays and then return lighter once indoors.

Photo-polar lenses are a combination of the two treatments above, blocking out the glare of the sun while also adapting to the daylight. Transitional lenses are great if you don’t want to be carrying multiple pairs of sunglasses but note that not all of these lenses adapt if you’re driving as a windscreen can block out UV rays.

Mirrored lenses feature a mirror coating (or flash coating) that reflects the sunlight hitting the surface stopping the sunlight from reaching your eye. These type of lenses are gaining in popularity and are most noticeable on the ski slopes.

Lens Colour

Monokel Nelson Bottle Green

Colour lenses have been gaining popularity in recent years, but did you know that the colour of the lens can actually have an impact on how you see?

Blue lenses – improve colour perception, defines the contours of colours.

Green lenses – add warm tones to what you see and improves contrast, which also reduces eye strain.

Yellow and Brown lenses – best for judging depth perception, red and green tones are easier to see and reduces blue light.

Grey lenses – most realistic in delivering the truest colour perception.

If you want to seeing varying light conditions, opt for the gradient effect, this makes seeing variation in light conditions easier.


Sunglasses lenses come in a variety of materials, from glass to plastics. Glass lenses offer the clearest vision and are more solid and scratch resistant, however they require more care and attention, don’t go throwing these in your bag!

Plastic lenses can be made of either polyamide, polycarbonate, or a material called CR-39. Polycarbonate is the lightest and most resistant alternative to these plastics, whereas CR-39 is the most widely used and go-to material for polarised lenses.

When it comes to looking at the frame materials you can either find them made from metal, nylon fibre, or acetate, although wood is slowly making its way into the industry for its sustainability properties.

Nylon fibres (plastic) is a resistant and versatile material, however, takes a lot of energy to produce so is not as environmentally conscious as some other materials. Metal offers a clean and classic look and is favoured for its resistance properties.

Acetate is becoming more popular as it is a non-petroleum-based plastic composed of mainly natural ingredients. Acetate sunglasses can be less damaging to the environment. Check out these Monokel sunglasses made from plant-based acetate here. 

Choosing A Pair That Fits

When it comes to picking a pair of sunglasses you should consider your face shape and how the style will compliment your face. A good rule to stick by is that sunglasses should have the opposite shape to your face, to compliment it and to accentuate your features.

Try measuring your face to determine your shape, sometimes even just tracing around the part of your face that is visible everyday is a great way to determine your shape. There are four main face shapes for you to keep an eye out for.

Round – cheekbones and face length have a similar measurement, soft jaw angle. Slim angular sunglasses allow your face to look narrower and longer.

Heart – jawline is long and pointed, chin is the smallest point of the face. Browline sunglasses that are wider at the top than the bottom help focus the centre of your face. Avoid thin frames as you want to bring the attention upwards.

Square – all measurements are fairly similar, jaw angle is sharp. Opt for rounder frames to help soften the features or embrace your lines with edgier frames to reinforce the sharp features of your face.

Oval – face length is larger that the width of the cheekbone and forehead is larger than jawline, angle of the jaw is rounded. However, this face shape is compatible with most frames and lenses.

At Copperfield we have a selection of sunglasses check them out here.