Each brand of sunglasses usually has its own anti-counterfeiting mark, or anti-counterfeiting code, and some also have anti-counterfeiting telephones, such as sunglasses on Su Po. If it is genuine, each picture has a unique security code, just like a person's ID card. The words and trademarks on the temples are also very clear and neat, which is not easy to wear. Another important anti-counterfeiting sign is that as long as you blow into the lens, the trademarks of four swans will appear.

Sunglasses are usually these methods to distinguish between true and false, I hope it will help you.