Why do skiers often wear sunglasses while they are skiing

They do it for personal protection, while they are skiing rocks can fly though and without personal protection the can get injured or even killed. That why they wear glasses for personal protection to avoid being injured in the eye.

For example if you are cooking and you want to take something of the oven, you would likely wear some hand gloves to avoid burns, that's the same with skiers.  

as we probably am aware that our atmosphere or air have various levels, each level has different gasses, and each gas has another porousness. at the point when the light originates from lower porousness to higher penetrability, it alters its course. with the goal that implies that when the light originates from the moon to the earth, it alters it's course a lot more occasions. it essentially implies that the state of the light piece of the moon is changed on the earth.

not copied too! hope this !

joke:

h o h o hope you have a merry christmas!