Answer:
I make everyone blind. You can't see me but I will always come back for you. What am I?
I am the black child of a white father a wingless bird flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me even though there is no cause for grief and at once on my birth I am dissolved into air.
Flat as a leaf round as a ring. I have two eyes but can't see a thing.
I go in dry and come out wet. The longer I stay in the stronger my surroundings get.
I fly forever Rest never.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.