The sunglasse for climbing the Everest should at least live up to the following requirements. First of aal, the sunglasses should be able to screen off the extremely powerful ultraviolet rays on the Everest in case of burned eyes. Secondly, the sunglasses should be able to be frost-proof and antifogging with good perspective effects. Thirdly, the sunglasses should be able to prevent the cold wind on the Everest from irritating the eyes. And the sunglasses should also be able to prevent the eyes from the intense reflection light of the snow which can easily eye strain and snow blindness. For more information about the sunglasses for Everest, you can refer to the following web site first for a more detailed look.