Built for hard light
Above the snowline, light comes from every direction: from the sky, off the snow and off the ice. Summit uses a spherical shield lens that curves on both axes for a wide view with less distortion at the edges. Ridge wraps a single cylindrical shield far enough to cut side light on its own. Both add a removable brow guard and side panels for the brightest days, and both come with a polarized category 3 lens or a photochromic one.
On glaciers and at high altitude, some conditions call for an even darker category 4 lens. Our guide to lens categories explains the difference, and how photochromic lenses work covers why they darken more in the cold.