HOW TO BUY SUNGLASSES

Whether for casual or sporting use, sunglasses are indispensable for keeping the sun’s harmful rays out of your eyes. But sunglasses can be fashion accessories too. Here are some tips on getting sunglasses that not only enhance your looks, but also afford you the best eye protection.

Picking out sunglasses that suit your face

The advice of choosing sunglass style based on the shape of your face is perhaps the oldest and most popular. There are a lot of charts and videos online showing you how to do this. Basically, this method relies on contrast aesthetics: If your face shape doesn’t have a lot of sharp angles, go for angular; if angular, go for glasses with more curves (‘Wayfarer’ styles consists of a top with angles and curved bottoms).If you have a sharp chin, offset it with frames that emphasize the horizontal. If your face is long, make it proportionally shorter-looking with larger frames). The trick is finding out what shape your actual face is, when viewed head on: Oval, square, round, heart/diamond-shaped. These shapes are mostly defined by your forehead, cheeks, and chin (less by your jaw since they are further back of your face).

But, once your face is viewed at an angle, these face shapes disappear. Your face may look round head on but angular when viewed on the side. And few people would only get to look at your face head on so nothing beats trying on the sunglasses you like and looking in the mirror at different angles to see how good you look. Your choice of sunglass style is also affected by the look you’re aiming for and the amount of eye protection you wish to have and sometimes the two don’t go together. For example, in order for you to show more of your face, you’ll naturally choose smaller (flatter or narrower, depending on how you look at it) sunglass styles but this lets in more of the sun’s rays at the sides of the sunglass. On the other hand, wraparound style sunglasses may offer more protection but some wraparound styles may look unflattering to your face shape.Still, nothing beats actually trying sunglasses on for shape and size.

Sunglasses size chart

Speaking of size, face size is different from face shape.Pick a sunglass size that proportionally complements the size of your face. If you have a small face, wearing too large frames would tend to overwhelm your face. How are sunglasses measured? This is where frame size comes in. Also known as the ‘eye size’ the right frame size for you depends on the width of your face (‘face size’), from temple-to-temple. Different face sizes have different suggested frame sizes, like this chart:

Face Size (temple to temple) Suggested Frame Size Frame Description
115mm or 4.5 inches 49mm Small
127mm or 5 inches 52mm Medium
130mm or 5.125 54mm Medium
135mm or 5.25 inches 55mm Medium
140mm or 5.5 inches 57mm Medium
146mm or 5.75 inches 58mm Medium
152mm or 6 inches 61mm Large

 

Although nothing beats trying out sunglasses personally for the right size, you won’t be able to do that on a website so the frame size is what you should look for when buying sunglasses online. Note that wraparound sunglasses fit more snugly with your face size, so you can go up or down a notch on these suggested frame sizes and still find a nice fit.

If you have a favorite sunglasses, you can try looking for the frame size inside the temples (or arms), where important information is usually printed. There are usually three numbers corresponding to frame/eye size (from 40-62), bridge size (from 14-24), and temple/arm length (from 120-150), in in that order.The temple/arm length is not your temple-to-temple face size but is close enough (since temple/arm length usually spans across the back of the sunglasses when it is folded). Sometimes the eye size and bridge size are separated by a box symbol and may be printed on the sunglasses bridge. Ignore numbers accompanied by letters since these are color/style codes. This information is often not found in cheap sunglasses.

Types of sunglass lenses

Sunglasses lens types are classified based either on style, the lens material itself, the tints and coatings applied on them, or the lens technology built-in to the lens.How sunglasses workfor you depends on the material, styling, and coatings used on the lenses.

Based on style

Style-wise, lens are classified mostly based on the shape of the lens frame, hence they range from the common geometric shapes (e.g. circle, square, rectangle, heart, star) to less common, fanciful shapes (there are frames shaped like a playing card). The style names can also come from the purpose for which the designs were originally intended (e.g., ‘shield’, ‘biker’, ‘aviator’, ‘wayfarer’) Here is a chart of the most commonly encountered ones (from Visual.ly):

how to choose sunglasses shape

Based on lens material

Usually, sunglass lenses are either made of optical grade glass or shatter-resistant plastic (e.g. polycarbonate, polyurethane, and acrylic). Sport sunglasses (to reduce glare in skiing or surfing, for example) are usually made of plastic.

Glass

Glass, especially optical grade ones, afford the best distortion-free finish and scratch resistance (some glass lenses are virtually scratch proof). Naturally this makes them more expensive than plastic lenses. But, since glass can break, glass lenses are usually unsuitable for rough sport – or sports that, even if not rough, may still hit you in the eye with a tough object (golf, for example).

Plastic

Plastic lenses usually have the ability to block 100% of the sun’s ultraviolet (UV) rays without the need for a special coating. Here are the most common plastic lenses available.

Polycarbonate

For shatter-proof sunglasses, polycarbonate lenses are the material of choice (even aircraft windshields are made out of them). Polycarbonate isn’t as scratch resistant or optically clear as glass though, although the next generation of lens plastics combine the best qualities glass and polycarbonate. Polycarbonate lenses block all UV rays without the need for special coating

NXT Polyurethane

NXT lenses are the NeXT generation of sunglass lens materials. The polyurethane material is trademarked as Trivex NXT and is manufactured in a patented process. NXT lenses have the clarity and scratch resistance of glass and the lightness and impact resistance of plastic. NXT lenses are even tougher than polycarbonate but are also costlier than glass (Apache military helicopter windshields are now made from NXT).

Acrylic Lenses

Acrylic is a classic sunglass material. It has less optical clarity and durability than polycarbonate. However, acrylic is an inexpensive choice, and is usually the material found in very affordable sunglasses for fashion and eye protection.

Based on tints/coating

Coatings are either for giving your sunglasses the desired color or to reduce glare.

Tints

Lens tints not only gives your lenses a desired color, they also afford the eye certain advantages. Depending on your purpose, they may give excellent contrast or depth perception at the expense of showing you the true colors of what you see (color distortion).

Brown

Brown tints enhance contrast and depth perception but distort the colors in exchange. This could result in eyestrain when worn for long periods.

Yellow/Gold/Amber

These lenses amplify available light so are best for low light conditions. They also give good contrast and depth perception but, since they amplify light, they don’t give much protection from bright sunlight. Good for snow sports and other activities that have low lighting.

Rose/Vermilion

Amber and rose/vermillion lenses are also called ‘blue-blocking’ lenses since they absorb blue light which, some studies say, can increase the risk of eye damage like macular degeneration. Rose lenses also give excellent contrast and cause very little eye eyestrain when worn for longer periods. Good choice for skiing, hunting, boating, and when flying aircraft.

Blue/Purple

Most blue/purple coated lenses are just for fashion purposes and don’t really enhance contrast or depth perception. Moreover, they let in blue light, which many believe can harm the eyes over time.

Grey/Green

These enhance contrast without distorting colors. They cut glare and also enhance depth perception without causing eyestrain. These are good for driving. Most ‘black’ tinted glasses only look black because they are tinted very darkly. They are actually tinted a very dark grey or green.

Gradients

Gradients merely refer to the deliberately uneven tinting of any color – some parts are tinted darker and some parts lighter. Most gradient lenses are tinted darkest from the top and lightest below. This compromise protects drivers from overhead sun and glare while allowing them to clearly see their dashboards in low light. Some sunglass lenses have double gradients: the lightest areas are in the middle part while the top and bottom are darkest. This protects the eyes from glare both from above and below. Good for spending a lot of time around snow, sand, water, or concrete but you won’t want this for downhill skiing since you need to see where you’re going better.

Special coating

UV Protection

Aside from style, material and color, what to look for when buying sunglasses is UV protection. Polycarbonate lenses have built-in UV protection while others need a UV coating. Go for lenses that are labeled as giving 100% protection from UVA and UBV rays. Photochromic lenses already have UV protection although they turn dark slowly than already dark lenses. For best UV protection, go for sunglasses that protect your eyes from every angle (like ones with large lenses with wraparound frames) – this can impact style, however.

Glare reduction

Glare reduction can be achieved in lenses by having polarized coating or an anti-reflective coating.

Polarized lenses reflect the glare off water or solid objects. They are therefore popular for water sports like boating and fishing. They however, tend to also polarize the light coming from LCD displays like smartphones or certain car dashboards.

Anti-reflective coated lenses reduce reflection coming from the back of your lenses, giving greater comfort when using the computer for long periods and sharper vision when driving at night. Anti-reflective lenses can be tinted but they are usually found in clear glasses.

Mirror coatings

Mirror coatings (also called ‘flash coatings’) reduce the amount of light entering the eyes. They also prevent people from seeing your eyes. They are therefore good for activities in very bright light sun. The metallic coatings can be of any color – silver, gold, blue, pink, for example. The actual colors that get into your eyes depend on the color of your tinted lens – which are usually of lighter tints because the addition of mirror coating makes objects appear darker than they are. These lenses are good for eyes sensitive to bright light.

Photochromic lenses

Also called ‘transition lenses’, Photochromic lenses are clear (or almost clear) indoors then slowly darken when exposed to sunlight (specifically the UV rays in sunlight). They save you from having to buy clear glasses for indoor use and sunglasses for outdoor use. However, since most car windshields already reflect UV light, most photochromic lenses do not darken inside cars. However, some modern photochromic lenses can do this since they are also sensitive to visible light.

Where to buy sunglasses

This question is usually asked when buying sunglasses online. If you have gotten this far, may we recommend our very own Sunglasses Warehouse? Here, our sunglass lenses are complemented with a choice of aluminum, titanium, monel, stainless steel, cellulose acetate or cellulose propionate frames.These are all quality sunglasses at reasonable prices. While the prices of sunglasses sold in retail stores have been going up and up, we work to give you the freshest designer sunglasses at the right price. Choose a pair you love now.

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