When buying sunglasses, you usually don't think about technology being a feature. Serengeti sunglasses are a creation of Corning, Inc., the leader in optics and glass technology. When I was employed by Corning, the Serengeti glasses were introduced (Corning since sold the business but it is still the same product). It was truly a novel, and in many ways, technological breakthrough. Take a few minutes to look at the features in these sunglasses. You will not find another product like it on the market. Features like blue light filtration, polarization, spectral control, distortion-free optical glass,uv blocking to name a few. Corning engineered these features into the glass, not a coating. Needless to say, I am sold on Serengeti. They are the best sunglasses available today. Take care of your eyes, you only have one pair.