From the Climbers Guide to Everest: “This painful state comes from the sun burning your eye cornea. It occurs if you don’t wear sunglasses at altitude.When climbing on oxygen, the warm and moist breathing air will escape your oxygen mask upwards and sometimes clog up your goggles, especially upon climbing down. Your choice will then be to climb ‘blindfolded’ or remove the glasses…” MORE âž²

(Disclosure: When I was a kid Styx was one of my favorite bands.)