First of all, your mountaineering sunglasses should have 99-100 percent UV protection to shield your eyes in the long time mountaineer. The function of blocking the light reflected from snow and mountains from all directions is also important. Your mountaineering sunglasses should also protect your eyes from dust, rocks and debris, so wrap-around types are preferable. Polarized lenses should be taken into consideration, for they can reduce the glare of snow, ice and water. It is better for you to choose shatterproof sunglasses which can withstand the outer forces that usually come unexpectedly. When you are on high altitudes, you will suffer additional 10-60 percent of visible light which will cause great harm. At this time, sunglasses with mirror coating will help you to have a comfortable feeling. I recommend Julbo brand to you because it is a professional manufacturer of sports equipment with a long history. This is its official website:
Just like what you said, you are enthusiast of mountaineering. When you are hiking, the sunshine may let your eyes uncomfortable, sunglasses can make things better with their unique functions. Sunglasses for moutaineering are various, but they have features in common, such as anti-fog coatings,wrap-around lenses and removable side-shields.
If you decide to buy one pair of sunglasses to shield your eyes when you climb mountain, you could choose the ray ban sunglasses with polarized role. You will find that the ray ban sunglasses are so cool at the design. In addition, they will be so good at the quality which you could wear for many years. You could also find that the ray ban sunglasses could protect your eyes from the uv rays in the strong sun lights at the top of the mountain.