Well, to judge whether they are fake or not, there are some tips you can follow. Lacoste's famous trademark symbol is its Lacoste crocodile logo patch. This is one of the easiest ways to spot a fake. A genuine Lacoste crocodile should be very distinct and should show scales, claws, and teeth. Any variation from this detailed standard should be deemed a fake. Also, you should know that Lacoste is a high end, fairly expensive designer brand. As such, prices are usually high and for good reason since the products are usually of very high quality design and material. If you are only paying cheap price for a pair of sunglasses, you should be careful about it. Of course, you can ask some professional person to determine it for you. Their advices are appreciated.
