Answer:
I'm the son of water but when I return to water I die. Who am I?
You'll have to consult an optometrist if you want to improve this.
What time starts and stops with an “n”?
The buyer doesn’t want it, the producer doesn’t need it and the user doesn’t know their using it.
What gets broken if it’s not kept?
People take me on walks and I run and have fun. What am I?