Compared the specially made skii goggles, sunglasses do not provide the same seal around the eyes and against the face. Even if you wearing sunglasses, you still leave your eyes at a high risk for problems with wind, ice and other hazards in the air when you skiing. Besides, most of sunglasses are not fasten to the head as well as goggles do. In addition, compared with goggles, common sunglasses are break easier.
There are some disadvantages when you wear sunglasses for ski. Sunglasses cannot protect your eyes from wind, ice and other hazards on the slopes because there are some space between sunglasses and your face. Besides, your face may get colder if you wear sunglasses for ski. Moreover, sunglasses are easy to fall off your nose and get broken if your sunglasses are made of glass because they are not fastened to your head. Therefore, the best way is to wear ski goggles when you go skiing.