Discount Eyewear Can You Tell The Difference Between Fake And Authentic Designer Eyewear?

Can you tell the difference between fake and authentic designer eyewear? - discount eyewear

I recently bought a Marc by Marc Jacobs show online. It costs about 140 USD (a discount of 40% had, as dealers).
The problem has disappeared "in Italy," written in the temple made when sweat easily. But the code-name (EC MJ 054 807 135) in the same place does not exist. Thus the "Marc Jacobs" is written (and hopefully will not disappear). Is this a sign of piece imitating the designs?