The Costa Del Mar Performance Fly Line Sunglasses integrate aggressive, wide-coverage tracking capability with advanced marine design optimized for fly fishing and open-water angling. This premium model pairs a robust Matte Chesapeake Blue XXL frame with elite Blue Mirror 580G polarized glass lenses engineered specifically to combat blinding overhead sun and intense reflection. Costa's proprietary 580G Lightwave glass technology provides distortion-free optical contrast while actively filtering out harsh yellow light to heavily minimize eye strain over long days on the water. The specialized frame configuration uses durable bio-resin materials equipped with premium side-shield geometry to block distracting peripheral light leaks and glare. Built to retain its precise alignment through challenging marine environments and high-heat conditions, Costa reinforces these high-performance glasses with their limited lifetime manufacturer warranty. Costa Del Mar Performance Fly Line Men's Matte Chesapeake Blue Frame Blue Mirror 580G Polarized Lens Sunglasses 06S9129-91291864