Answer:
Sometimes I am loud. And viewed with distaste. Poke out my 'eye', then I'm on the front of your face.
The man who made it didn't need it. The man who bought it didn't use it. The man who used it didn't want it.
It regulates our daily movements, but it feels no interest in our lives. It directs us when to come and go, but does not care if we pay attention. What is it?
A dagger thrust at my own heart, dictates the way I'm swayed. Left I stand, and right I yield, to the twisting of the blade.
I have one eye. See near and far. I hold the moments you treasure and the things that make you weep.
What is yours but only used by others?