The Trek sunglasses are the go-to eyewear for general and ski mountaineering. Transition lenses keep the light transmission optimal and a wrap-around style blocks the U/V light from melting your face. The glasses feature air vents on the lenses to prevent fogging, and also allow airflow underneath. In addition, you can remove the side wings to further increase the venting on warm spring days. The glasses hug your head well with adjustable nose pieces and temples. The Julbo Treks are light and have photochromatic lenses that adapt to the sunlight. Perfect for race, touring, scrambling, you name it.