Quality ski goggles help improve your vision by reducing glare, adding contrast in low light. They also help to protect your eyes from UV light, stop debris and snow from getting in your eyes and most are made from shatterproof Poly-carbonate so they don't break apart in a crash.
A lot of goggles now have interchangeable lenses, so you can get the right lens for the right conditions.
Buy a Dragon X2, X2s or NFX2 Goggle and get 30% off an additional lens. See product page for discount code.