When you head out to the beach, it's second nature to pack your sunglasses and sunscreen. When you're packing for a place with cold temperatures and thin air, however, the need for sun protection may not immediately spring to mind; yet studies show that UV-B levels in high elevations are approximately 60% greater than those at sea level. On a clear day, a person of average complexion in Vail, Colorado will begin to develop a sunburn after a mere six minutes of exposure [source: AAD].
By the same token, water-loving contact lens wearers would never forget to pack their swim goggles on a beach trip, but it may never occur to them that parched area might wreck as much havoc on their contacts as salt water. This is not to say that you can't wear contacts at elevation, but you will need to take special precautions. You should carry eye drops and take extra care when changing your lenses since the risk for developing microbial keratitis (corneal ulcers) is greater at altitude [source; BaseCampMD]. You'll also want to carry backup eyewear in case your contacts fail.
Now that you're all packed and ready to hit the trail, it's time to go over what to eat and drink once you get there. Find out what to munch on the mountain next.