It is best if you pick yourself a few points for different situations. In order to spend a long time on the sea beach, the most suitable will be enough glasses with glass tinted lenses. However, when you are ready to play a game of beach volleyball, fragile glass can be very dangerous for your eyes, so in this case it is better to use glasses sports type, light frame with nylon and plastic lenses.
In general, what is the difference between the darkened plastic and glass, as they protect your eyes? Of course, plastic lenses after hitting a volley ball does not fly away like glass into small pieces, not to injure you. But here's the real glass does not distort visual perception and does not transmit ultraviolet rays.
Shape sunglasses are selected depending on the type and shape of your face; for example, to fit a fairly large elongated frame. On the broad face in a circular rim glasses are unacceptable, if you do not want to look like a cat Basilio. This frame is suitable zaovalennymi or if you have a wide chin and forehead.
Choose sunglasses better not alone; familiar people, and not the seller will tell you what points you are most. Themselves meticulously consider all the details of design labels, quality of frames and connection handles. And, of course, better to buy sunglasses in specialized stores, and not on the market. There (in the store) is still less likely to run into a fake.