Yes, they do produce flip up sunglasses----the model Thump, and Thump 2 has flipping up lenses. And, one of my friend bought a pair of them, they flip up "gull styleâ€, As I can see, It is quite practical, however sometimes silly to flip them up.
But if you do like it deeply in your heart, go ahead just have a try.
It seems that Oakley sunglasses is your type. Anyway, I can see that they indeed sell some flip up sunglasses. Personally speaking, it find the sunglasses quite fashionable and amazing. And Oakley is one of the most reliable eyewear producers, their sunglasses are of great quality. If you want to get some of them, you may visit some optical centers , or visit some websites full of sunglasses, such as Ebay and Alibaba.
If you are looking for good quality flip-up sunglasses you should check out Scheyden Eyewear's patented titanium flip-up! I work for the company, and the quality is the best. They are hand crafted in Japan. Check them out at www.scheyden.com
If you are interested I can give you a coupon code :)
Well, it's hard to say whether oakley makes filp up sunglasses or not. Because I made a deep surfing online and found so many online shops have oakley flip up sunglasses on sale. However, most people said those oakley sunglasses are real, while the others hold the opposite views. Personally, I believe that oakley doesn't make filp up sunglasses for high technology required and solid frames they created. Meanwhile, oakley official website also doesn't admit that there are any oakley filp up sunglasses which are on sale, even no any product introduction on this site. So if you wanna buy a pair of filp up sunglasses of brand oakley, be careful.