Answer:
I'm light as a feather yet the strongest person can't hold me for more than a few minutes. What am I?
I am whole but incomplete. I have no eyes yet I see. You can see and see right through me. My largest part is one fourth of what I once was.
Lovely and round, I shine with pale light. Grown in the darkness, a lady's delight. What am I?
I am so delicate that even mentioning me breaks me. What am I?
So simple, that I can only point. Yet I guide men all over the world.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?