How to Choose The Best Lenses For Your Sunglasses
The key to a great pair of sunglasses is finding the right set of lenses to go with them. You want your sunglass lenses to fit properly, look great, and help correct any eye conditions you may have - but most importantly, you want them to protect your eyes against harmful UV rays. There are three important factors to consider when choosing the lenses for your sunglasses: lens material, lens color and lens treatment.
Sunglass Lens Material
The first plastic sunglass lenses ever made were constructed from a plastic polymer called CR-39. Polycarbonate lenses were later introduced in the 80's, and to this day, they are the most common material that sunglasses lenses are made of. Polycarbonate lenses are very popular because they are significantly lighter than standard plastic lenses and also more impact resistant, so they are less likely to break if you encounter any knocks and bumps. As a choice of material, polycarbonate lenses are great if you are choosing sunglasses for kids, contemporary sunglasses or for sport activities.
High-index plastic is the latest and greatest type of material used for sunglass lenses. They are even lighter, thinner and flatter than polycarbonate lenses. In fact, if you have a very powerful prescription then you may find that high-index plastic is the best type of material to choose for your sunglasses lenses.
Sunglass Lens Colour
Most people believe that darker lenses offer better UV protection, but you may be surprised to discover that the color of the sunglass lenses has no relationship to the amount of protection you are getting. This is because the coating which blocks UV rays is actually transparent, meaning that darker lenses do not necessarily offer the most UV protection.
However, the hue of your lenses still plays an important factor regarding visual performance. Some colors are more suited for certain activities, so it is still worth considering which lens color will be best for your sunglasses.
Generally speaking, darker sunglass lenses are a good choice if you are looking for lenses that will reduce glare but not distort color. These lenses will be great if you are likely to be wearing your sunglasses all day. Green lenses are also good for all day use as they protect your eyes while providing visual clarity that most resembles natural human eyesight. Brown or amber tinted lenses have a red tint which is known to enhance color contrasts, so they are best suited for sports or activities where accurate depth perception is key, such as tennis, fishing, golf and sailing.
Color enhancement does not only extend to full tinted lenses. Transition lenses, also known as photochromic lenses, are also available. These photochromic lenses darken when directly exposed to UV light and become transparent when not exposed, which is extremely convenient if you will be moving frequently between indoors and outdoors.
Sunglass Lens Treatments
There is an endless list of lens treatments which you can apply to your sunglass lenses, such as anti-scratch, anti-glare, anti-reflective, a UV protective coating, a mirrored coating or even a polarized coating.
However when it comes down to it, if you are investing in a great pair of sunglasses that you want to last for a long time, then it is highly recommended that you should choose lenses which have at least the first four types of lens treatments.
An anti-scratch coating ensures that your sunglass lenses will avoid being scratched and ruined by surfaces like sand, the inner contents of your purse or your shirt sleeve (because you know they always end up being cleaned that way). Anti-glare, anti-reflective and polarized lens coatings all enhance your visual quality and are great for activities where you will be under intense sunlight (i.e. exposure of more than 10 minutes) and need to reduce sun glare.
A UV protective coating is essential for protecting your eyes from harmful UV rays, sunglasses should have this coating. Mirrored sunglasses lenses deflect light, but they are often chosen for aesthetic purposes so it advisable to choose lenses which also have an anti-glare, anti-reflective and anti-scratch lens treatment applied.