First of all, you should check the brand which is printed on the frame of the Chanel sunglasses. The printed mark should be smooth and with no fault. Compared with the exact brand writing given on the internet, you can see whether it is the same. Then, you should check the balance of the sunglasses by putting it on the table to observe which will show the detailed manual work.
If you want to buy real chanel sunglasses and don't want to get fake chanel sunglasses, you shall first not try to get cheap one. You know, such famous brands sunglasses usually expensive, it is impossible to get real chanel sunglasses at cheap prices. And to get real chanel sunglasses, you can buy it from Chanel exclusive shop. Or just order it from their official sites. Hope this help.