Is this person whose namw appears on a pair of ''designer'' sunglasses the same person who designed them?

Not necessarily. Often, the name on designer sunglasses refers to a brand or label, which may be owned or endorsed by a celebrity or designer, but not imply that they personally designed the product. Many sunglasses are created by teams of designers or manufactured by third-party companies under a brand's name. It's important to check the specific details about the designer's involvement for clarity.