Polarized sunglasses

Polarized sunglasses use a special filter that blocks horizontally scattered light, which is the light responsible for the bright glare that bounces off a water's surface. Cutting that glare is what lets an angler actually see through the surface into the water instead of just seeing a mirror of the sky.

For fly fishing, this makes it possible to spot fish holding in a run, see subsurface structure like drop-offs and rocks, and even watch a nymph or leader drift, all of which are far harder or impossible to do with regular tinted sunglasses. Lens color changes performance too, with darker lenses suited to bright days and lighter amber or yellow lenses helping in low light or overcast conditions.

A frequent mistake is buying sunglasses that are polarized in name only or wearing regular sunglasses and assuming they work the same way, when only true polarized lenses cut glare effectively. Good wrap-around coverage also matters, since light leaking in around the frame's edges from above or the sides reduces how clearly the water can be read.