No matter what brand of famous and superior sunglasses, they all have the common characters. We can not give you the tip for the 100%'s assurance to define the real or fake of it, but we still have some points for you to choose the right one. Firstly, the best sunglasses have the great anti-ultraviolet function which would prevent the 99%'s ultraviolet. Wearing such kind of sunglasses, your pupil will keep the same no matter indoor or outdoor, in dark or bright place. Secondly, it will be very clear of the vision when you wearing the real sunglasses, your eyes will be comfortable and relax. Thirdly, the real sunglasses will be strong and durable. There have no flaws and scratches on the surface of glasses. The last one, the accessories, such as glasses cloth should be cotton make other than nylon, the details of the glasses box will also be exquisite. Ok, I believe your sight and taste. Follow your nose; it will be no issue to say the real from fake ones.