How to Choose Sunglasses
From lens material to optical coatings and frame construction, choosing the right pair of sunglasses is more involved than most people think. Educate yourself on the importance of eye safety and find out how to make the best choice for the occasion.
The light that you see from a light source or reflected off an object is in the visible spectrum, from about 400 to 790 nm (nanometers). This is the spectrum that standard sunglasses help to reduce.
Visible Light Transmission (VLT)
You may come across this term when researching sunglasses. It is the amount of light that reaches your eye through the lens. The smaller the percentage, the less light that is being transmitted through the lens. Standard sunglasses have a VLT of 15 to 25%. High altitude mountaineers who encounter more intense light because of the thinner atmosphere will sunglasses with a VKT of 5 to 10%.
Ultraviolet Light (UV)
The reason you squint when exposed to the bright sun is that ultraviolet rays can serious damage to your eyes if not reflected away. Sunglasses do not only protect your eyes from dirt and debris when out in the wild, they also prevent you from suffering ailments cause by long term sun exposure. One of the most common concerns for outdoors enthusiasts is the threat of getting cataracts. This is a gradual clouding of the eye that can eventually lead to blindness, and the best way to prevent them is by wearing sunglasses that block out 100 percent of UV rays. Adventurers must remember that eyes can be damaged on first contact with the sun, so even a small bit of exposure to UV can be detrimental.
Of course, squinting is never enough to provide the adequate protection needed to keep your eyes healthy for life. Another serious threat to the eye is known as keratitis. While this condition is relatively rare, its likelihood is tripled by long-term exposure to ultraviolet radiation. If not careful, sufferers can experience inflammation of the cornea noted by a momentary loss of vision and burning sensations in the eyes. In addition, the sheer heat of the sun can cause eyes to dry prematurely and lead to a host of other issues that can compound with extended exposure. For these reasons and more, sunglasses are as important as sunblock lotion when going outside in sweltering summer weather.
Remember, UV rays are not only a factor on sunny days - they penetrate through clouds and also reflect off of snow. Winter hikers and skiers should be extra cautious in the mountains where the atmosphere is thinner and allows more radiation to seep through. While grey skies and whipping winds may make you feel frigid, and you can never be too careful - for every 3,000 feet you ascend, UV radiation increases around 15 percent. Always look for sunglasses that mention UVA or UVB protection to ensure that your eyes are being kept safe from harm. Options like the Smith Mastermind will ensure that all damaging rays are reflected from your eyes dark lenses help you make sense of overwhelmingly bright mountainsides.
There is definitely visual appeal to having sunglasses with interesting lens types and colors, but there are reasons why every set of lenses is designed with these particular features. The curvature, material and materials of a lens will change the way a pair of sunglasses performs in the field, so do not spring for the shades you think might look the coolest - know how each type of lens distinct and you will be able to better match them with your needs once you head out into the outdoors.
To ensure you make the best sunglass purchase for your needs, first consider the material with which the lenses are made. This will be the main determinant of durability, weight and visibility of your shades, not to mention playing a role in their cost. Learn the ins and outs of the main types of materials used in today's sunglasses to make a more informed decision when it comes time to buy. These days, lenses are either made from glass, polycarbonate or plastic, and each have their own place in the outdoors.
Glass: The glass lenses of today are much better adapted for adventure than you may think. Gone are the days when glass lenses would distort and scratch overtime - they are now a great option for someone looking for a classic look that delivers performance as well. Glass offers premium visual clarity and is treated so that they will spider on impact instead of shatter. While you may need to replace a lens in this case, your shades will not be ruined for good, meaning you don't have to be apprehensive about hitting the mountains with this material. There are downsides to glass lenses, however. They are often heavier than their polycarbonate and plastic counterparts and will likely cost more to purchase and repair. Nevertheless, glass lenses like the ones found in the Costa Del Mar Seven Mile Sunglasses offer superior eye comfort and clarity for a diverse range of activities.
Polycarbonate: If you are an outdoors enthusiast who wants a hyper-reliable pair of sunglasses without breaking the bank, look no further than polycarbonate lenses to fulfill your needs. Where glass lenses might leave some adventurers weighed down and low on cash, polycarbonate guarantees low bulk, light weight, cheaper price and a virtually indestructible resistance to impact. The fact that this material is 20 times stronger and a third the weight of glass lenses is enough to get anyone interested, especially if they are trying to adventure on a budget. Although they are known to feature slightly less clarity than glass due to an embedded coloring process that differs from tinting, the UV protection and agile performance capabilities will be make polycarbonate an easy choice for highly active trekkers. For an inexpensive and long-lasting choice, look into Optic Nerve Waterdog Sunglasses. In addition to all the benefits of polycarbonate lenses, they also feature a hydrophobic coating which makes them extra water-resistant and easy to clean.
Plastic: Everyone has found themselves in the mood for a spontaneous trip and needing a pair of sunglasses fast and cheap. Plastic lenses are the perfect solution in a tight spot such as this. Although they are not known for their durability or clarity, plastic lenses are still lightweight and can offer enough protection from the sun to make them great for occasional use. If you are in a jam and your friends are beckoning you to get in their car headed for the mountains, pop into a convenient store or gas station on the way to grab a pair of of these shades for good measure. Otherwise, spend a little bit more to invest in the health of your eyes. Great polycarbonate sunglasses can be easily found for under $50 and will last for years while giving you a much better fit and field of vision than plastic lens alternatives.
Colors and Tints
The tint/color of the lens is more than just a cosmetic consideration. It affects how much light reaches your eyes, the colors you can see in the environment and the contrasts available in your field of vision. Here are the most common tints along with an idea of how they can effect your adventuring experience.
Brown: On a cloudy, grey day, brown lenses are a great choice because they can help you to see a wider range of colors and contrasts in the terrain. They will cut down on brightness without dimming your vision and cut out a significant amount of glare despite overcast conditions. A pair of Suncloud Roadmap Polarized sunglasses with brown lenses will give you the visual clarity you need when natural sunlight does not provide an adequate range of colors for the naked eye.
Grey: Perhaps the most commonly chosen lens color because of their classic look and highly adaptable light filtering capabilities, grey shades will give cut down glare in nearly any kind of environment while maintaining your depth perception for activities that require total precision. A pair of Native Eyewear Haskill sunglasses are a great choice for year-round use and will give you the most accurate representation of natural colors while giving you the protection from UV that you need on most outdoor escapades.
Green: Like brown and grey lenses, a green tint is a neutral shade that delivers all-purpose use while giving your eyes a realistic vision of the colors you perceive. Minimal distortion and enhanced light contrast make these another great choice for moderately bright conditions in either rain or shine, brightening shadows while minimizing glare. Guarantee yourself enhanced visual clarity by snagging a pair of Costa Del Mar Zane sunglasses with green lenses that will work well in every season.
Yellow: If you are trekking through rain or other dark, stormy conditions, a lighter yellow or gold tint will give you the improved depth perception and range of contrast that you need to stay on your toes. Although yellow lenses offer less light protection and will distort the natural colors in the terrain, they should be your go-to choice for when the sun is not shining directly on your environment. Make the best out of a foggy or hazy day by wearing Jumbo Race Zebra sunglasses that feature lenses with a condensation-shedding layer.
Rose: Popular for skiing and snowboarding, these reddish lenses offer a bright vision of the world regardless of the sun's position in the sky. To spend a day on the slopes while minimizing the harsh reflections of light off the snow, look into Julbo Suspect Spectron 3+ sunglasses and pick up on every detail of the terrain.
If you buy a pair of expensive shades, don't feel locked down when you choose a particular lens tint. Ask about interchangeable lenses and give yourself maximal adaptability depending on which activities you pursue. You will get a lot more out of your investment and enjoy a wider range of outdoor opportunities this way.
Many misconceptions surround the idea of polarization - essentially, these lenses block out horizontal light waves, making them ideal for anywhere that the sun reflects off of a flat surface such as a lake or ocean. Because reflections can align and intensify on water or long roads, you may find your current pair of shade lacking the adequate protection in these situations. Polarization is becoming a more common feature on all types of sunglasses, but remember to do your research first.
Frames and Fits
Last but not least, make sure that you buy sunglasses with frames that you find comfortable and will suit the requirements of whatever activities you prefer. For example, metal frames are low-profile and easily adjustable but are often pricey and less resistant to impact than nylon varieties, which may be better for high-speed sports that pose a greater risk. Nylon frames are also generally cheaper and feel weightless on your face when you need to focus on the moment at hand. However, because these frames are rarely adjustable, you must always try nylon before you buy to ensure that you get the best fit possible for your face.