Answer:
The buyer doesn’t want it, the producer doesn’t need it and the user doesn’t know their using it.
You'll have to consult an optometrist if you want to improve this.
The more I appear The less you see. So riddle me this: What could I be?
The King of Pop's stellar dance move
As strong as love, more dangerous than cancer.
When is it bad luck to see a black cat?
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?