|The author, rocking out his Spectron 4 shades in the bright light on Denali|
This leaves you with a bit of a dilemma, seeing as sunglasses generally are made for when the sun is out, right? Most sunglasses are just too dark to use when the clouds are out, making visibility even a bigger issue. Julbo USA realizes this issue, and as such have created glacier glasses with much higher visible light transmission. They use a lens system which range from Spectron 1 - 4, with the higher number eliminating more of the visible light. They have even created a lens system, which they callCamel, that is photochromatic - meaning it transitions between two different lens categories depending on the amount of light available.
This feature however, can price some people out of these glasses, and personally, I choose another option anyway. On long expeditions, I will bring 3 different sets of eye wear, for a variety of reason. The first, is a pair of sunglasses that have Spectron 4 lenses, for those days that are bluebird and the sun is out shining. The second pair, will have Spectron 3 lenses in it, and an anti-fog coating. I tend to find that when I'm in a white out, there is a lot more heat and moisture and my glasses will fog up. That is why it is most important to have an anti-fog coating on this pair.
|The author, with his Spectron 3 glasses - preparing for when that fog rolls in.|
My final pair, will be some goggles, with the highest visible light transmission possible. If I have goggles on, it is probably because the weather is so terrible and the wind is blowing so hard, that I will need to be able to see as much as possible. Smith Optics makes a great pair of lenses called the sensor mirror, which seem to increase contrast and really help with the flat light that can be found in a blizzard.
|Smith goggles with the Sensor Mirror Lens.|
The important thing to note, is that all of these glasses/lenses filter out 100% of UVA/UVB rays. The amount of visible light that is transmitted is a completely different story, which is why you can still remain protected while altering your lens to the current conditions. Additionally, you could very well get a pair of glasses with Spectron 3 lenses, and they would serve most all of your purposes. I choose 3 pairs of eye protection because I like to have redundancy in this system. If I, or someone else on my team, loses or breaks their glasses - there will be a back up pair. I would rather carry the extra weight of a second pair of glasses, than go snow blind.
|The author, covering up his skin and rocking a different pair of shades on the summit of Denali.|
Let's not forget the most important reason to carry more than one pair of sunglasses however. Sometimes it's nice to switch up your style while on the mountain!
--Andrew Yasso, Instructor and Guide