I want to buy a pair of sunglasses for my kids, he loves skiing either, a pair of polarized sunglasses maybe a good choice for him. but I don't know what should I consider when choosing sunglasses for kids,and what kind of accessories should I buy?

A piece of cleaning cloth, solutions and a protective, hard-shell case are all good option for kids,you may choose retainers either, These can be attached to the temples of the sunglasses, they can make the sunglasses hang from the neck when they are removed or even knocked off, Just suggestion!