I obviously couldn't bring my contact lenses - too much crap to go along with it so I'd have to bring my eye glasses.
Why?
1. So I could see and function like a normal person! I don't want to fall off a cliff or step on a poisonous snake or something like that.
2. Can be used to create fire but only if it's sunny out. Remember burning ants with a magnifying glass in the summer? Oops - was that just me?