they do help are quality of life but they are not nesisary they wont really save your life in any way possible. but sight touch and hearing and important. if you cant see, you cant see that bus heading for ya! same with hearing, that helps you detect things near you and you can then talk to people better. touch is very important, becouse if you dont have touch you wouldent know if you were being attacked or being hurt in some way. what can smell and taste do to save you?