Sunglasses are fine for sunny days, but on cloudy days visibility is poor and goggles are preferable. When it's snowing, goggles are a must. If you're a contact lens wearer, you'll probably want to wear goggles regardless of the weather due to the dry air.
Rent kid's ski-wear from Mountain Threads where you can build ski or snowboard outfit from the outside in. Select jackets and pants, accessories and base layer, right down to your socks, for a comfortable day on the mountain.