For a BOB, maybe a pair of sturdy glasses in a semi-hard case with a neckcord or elastic band would be more appropriate than spare contacts?

I'm just thinking that tired, on the move, in the elements and dark isn't the time to delicately balance a contact on your fingertip and try to figure out which goes in the right and which goes in the left eye. Nor would it be much fun to do the contact hunt in the great outdoors.

Dave