Well, as you can see,rihanna is one of the singers that are famous in Latin America. And from what we can see, the type of glasses she would like to wear is called studded sunglasses, which makes her appear to be quite awesome. And as a matter of fact, they are quite cheap if you don't care about brands. You could get a lot of cheap aviator glasses at Amazon, I have seen a lot of them .
It is the Morir Studded Sunglasses that Rihanna studded wears. The pair of sunglasses is black. They must be the designer sunglasses which are with the high price. You could go to the online stores with good reputation to have a search. You could also go to the near real store of eyeglasses to have a look. I strongly suggest you to go to the amazon to have a look. You may find the similar type there.