Answer:
I can be long or short. I can be grown or bought. I can be painted or left bare. My tip can be round or square. (one word)
Some try to hide, some try to cheat, but time will show we always will meet.
I am so delicate that even mentioning me breaks me. What am I?
Against the sun I protect your eyes and am often worn on the face of spies
I never sleep yet sometimes I weep. I can get angry or just be happy. Wherever you go, I will follow. No matter what you do, I will be there. I cannot die. What am I?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.