Let me get this straight I have nothing against fashion sunglasses. You wear them all you want, but if you are doing some sports then make sure you have the right equipment.
Would you wear a fashion top on a ultra-marathon or triathlon? If you are serious about sport then the answer is NO! You wear a specialist running or Tri top with the most comfortable, lightweight and "sweat wicking" material.
Then what about your sunglasses?
There is a difference between sports sunglasses and fashion sunglasses here is how to tell the difference.
1. STICKY AND ADJUSTABLE FEATURES
Sports sunglasses are designed to stay on your face when your doing sports. They have "sticky features" such as grooved rubber nose pieces and soft rubber temple ends.
Really good sport sunglasses (like AMO Sunglasses) have these features plus the temple arms and the nose pieces are adjustable.
Fashion sunglasses are designed to look good. They will not have adjustability and rubber temple arms or nose pieces.
In short, if you're doing your exercise with fashion sunglasses, they will slide around and fall off you face.
2. ENGINEERED MATERIALS
Sports sunglasses use materials that are "engineered" for the extreme environments in which they are expected to perform.
This means the frame material is made from a plastic polymer called TR90. TR90 is stronger, more durable yet flexible than the basic plastic material the fashion sunglasses are made from. This means they will not break as easily when they are thrown around during exercise or in your ruck-sac.
Also TR90 is much more chemically and UV resistant than a basic plastic frames (that fashion sunglasses typically use). This means it will not degrade when exposed to UV light and chemicals such as suntan lotions and hairspray.
The problem is, it is very hard to tell the difference between TR90 and plastic (as they are both different types of plastic) and unless you buy your sports sunglasses from a reputable brand (like AMO Sunglasses) you will find it hard to tell the difference.
3. SAFE LENSES
Being safe during your exercise is essential. This means the sunglasses lens must have a number of functions.
(1) They must have a good impact resistance. This means that if an object (like a stone or branch) hits the lenses they will not shatter and protect your eye. Good sports sunglasses are made from 2mm thick Polycarbonate or (even better) Grilamid NXT lens material; both have superb impact resistance.
Fashion sunglasses lenses are made thinner plastic (which will shatter) and a material called "CR39" which easily shatter on impact. What this means is that these lenses are much more likely to break and the object or the sunglasses lenses could get in you eye.
(2) Really good sports sunglasses have special coating on the lenses which means they stay clearer for longer. These sports sunglasses coatings include an hydrophobic coating (which sheds water such as rain and sweat) and anti-fog coatings.
So if you are serious about your sports equipment then get serious about your eyewear. Choose sport sunglasses that are suitable for sport.
So these are my views. If you have any comment then please let me know your views.
Tim Hallworth is a triathlete, adventure racer and ultra marathon runner and with his wife Fenny is co-founder of AMO sunglasses.
There are also similar blogs and artless about sports sunglasses and mutisports on the AMO Webpage at http://www.amosunglasses.com/latest/blog.