At The Sunglass Fix we know how important great optics are in a pair of Crack sunglasses. That is why we have developed precision Polyamide lenses with the optical clarity of glass. We strive to make our lenses as good if not better than your original Crack lenses. You have taken the time to find a pair of Crack sunglasses you love. We are here to make sure they look as good as the day you bought them.