Who Am I?

I am born in the eyes
but I die in the cheeks
I come when you cry
and I leave when you sleep
Some wipe me away to hide when they're week
but some let me stay
and there I will seap

I am sent from the brain
like a soldier to war
I face the cruel world
like an infant outdoors
I run down your face
to gather the plain
I wash it away
to help you maintain

My mission is simple
my goal is you
My journey is endless
my progess is true
I am a teardrop
I have no fear
Whenever you need me
I will be here.