Well, generally speaking, you should know that there are many tips you can take to spot the fake ones. But in my opinion, the most common and best way is to check the label. First, you should know that they are made in Italy. So you can check the label which should be written with the words "made in Italy". Also, you can check the warranty. Also, Ferrari sunglasses are very famous all around the world. These sunglasses have good design and achieving high quality and reputation. In this way, they can not only ensure you to get clear vision, but also can express your personality. Also, Ferrari sunglasses can be used to have some activities outdoor, so that you will not be hurt by the UV rays. Anyway, by wearing them, it is safe and comfortable for you. Of course, you can buy them on online shop which is cheaper than the real ones. For example, you can buy them at http://www.smartbuyglasses.com/designer-sunglasses/Ferrari/. It will cost you about 250 dollars. So I think it will be a good choice for you to have a try.