• Adequate eye protection for a variety of activities (flying rocks from mountain biking, falling ice while mountaineering and ice climbing, etc...)
• Adequate Ultra Violet (UV) protection especially for mountaineering and above tree line trail running
• Light weight and comfortable---a must for trail running
• Form fitting to your face and does not slide off your nose even during heavy sweat and while performing all your activities
• Does not fog up in high intensity activity
• Inter-changeable lens for limited visibility (high contrast amber for dusk and dawn) and night movement using clear lens to protect the eye from branches and anything you might run into during night running, biking, or trekking

Bottom Line: I have not found a pair of sunglasses that fulfill all the requirements listed above, but use specific mountaineering classes with higher UV and wrap-around eye protection for above 14,000 feet and a smaller form fitting pair for Nordic, telemark, Alpine Touring (AT) ski training, ice climbing, and trail running. The smaller pair covers less of my face and has less of a tendency to fog up and has inter-changeable lens and specifically clear lens for night.

• Snowshoes
• Oakley Sunglasses
• Smith Sunglasses
• Large hydration packs
• Small hydration packs
• Technical Day Backpacks