I have a pair of prescription sunglasses. I think prescription sunglasses are more convenient for me because I have some vision problems. I need the prescription glasses or contacts to correct the vision problems for me. But a pair of prescription sunglasses can correct my vision problems as well as block the harmful UV rays for me, why not choose a pair of prescription sunglasses. You can have a look at http://www.firmoo.com/answer/question/121.html. You asked the same question as other people did. If you want to find more answers. I think this will be helpful.
If you have some vision problems, I suggest you to buy a pair of prescription sunglasses. Prescriptions sunglasses can help correct your vision problems as well as block harmful UV rays from the sun. But if you don't have any vision problems, you can buy a pair of regular sunglasses. But recently I am thinking about buying a pair of photochromic lenses glasses, because I heard that they can work as a pair of sunglasses in the outside and a pair of prescription glasses inside. I think a pair of photochronic glasses can provide me all the functions and I won't need to take off sunglasses and put on my prescription glasses when I am in the house. it is so convenient. But I am still thinking about that because I think they are a little expensive and I just bought a pair of prescription sunglasses last week.