Yes, apart from the Calvin Klein sunglasses, other brands sunglasses also do have many fake ones. At the same time, we have to find some ways to tell whether they are fake or not when buying, otherwise, most of the famous brands will be end in the near future. As a sunglasses fan, I know some certain methods to tell, and now I will take the Calvin Klein sunglasses as an example, you can get the answer from the weight of the sunglasses, because we all know that the real ones are made from the high quality material while the fake ones are just made from the poor quality, the authentic Calvin Klein sunglasses are heavier than the fake ones. Also, this is the reason why you had better not buy online. Besides, you can also check the log carefully, if the logo is out of place or glued on, then there are much possibilities that you have bought, or will buy, the fake Calvin Klein sunglasses.