Duduma Sunglasses via Amazon offers Prime members the Duduma Unisex Polarized Sports Sunglasses, model no. TR46, for $22.99. Coupon code "ZVSWID28" drops it to $12.99. Plus, Prime members bag free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $6.53.) That's $79 off and the lowest total price we could find. They feature 100% UV400 protection, 7-layer lens, and adjustable nose pad.