Blocks Blue Light from All Screens Relieves Eye Fatigue by 90% Very Easy to Install into Glasses Apex Lenses are 1.5mm thick (50% thicker than the competition) Crafted In The USA Apex Lenses are designed, tested and manufactured in the USA. We have unrivaled clarity, protection, and longevity than the other guys. We use only the highest quality materials and precision to keep your sunglasses at peak performance. Our lenses are 1.5mm thick, which are nearly identical to your original pair. We stand behind our products and offer a 30-day warranty from the purchase date. If you are unhappy for whatever reason, we will refund your purchase for the full amount.