I need glasses and in the past few years have needed bifocals - can't see or read without them. My prescription sun glasses have become expensive. I travel a lot and over the past few years have lost three pairs of prescription sun glasses - probably more than $1,200 worth of glasses. This last time I just wanted something inexpensive that if I forgot on the airplane would not be a painful loss. These work great. Good sun protection, stick to the top of my head or on a baseball cap when not needed, and offer good cheap protection. I'll probably never get another pair of prescription sun glasses. Great product. They look big but I don't care. The price is right and the functionality is excellent.