Answer:
Both guys and women enhance their visual organs with this item.
If you agree give me one of these.
Split me in half, and you get me and another me. What word am I?
Though I should be unique, you've made most of us the same. I would be stronger, if my characters were stranger.
What goes up and down without moving?
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.