It is always good to be able to see where you are going.  Have you ever gone into a dark room and tried to feel yourself around?  Maybe stubbing your toe or knocking something over looking for a light switch.   Hard to believe but that little switch changes everything.  Give it a flip and all of a sudden you can see clearly.  That is what vision is.  Vision helps us to see clearly.   Without vision we cannot see or know where we are going.