Polarized Glasses

The necessity of having polarized glasses as an important piece of equipment for the angler is the topic of discussion here. Polarized glasses, as opposed to regular sunglasses, allow us to identify key dynamics of a stream or river, such as where our quarry may take up refuge or a feeding lane. This prevents the angler from making a lot of blind casts and wasting valuable fishing time. The most common color used is a gray lens. Color of lenses vary from light gray to dark gray depending on the brand. Gray lenses are best at maintaining natural colors while minimizing brightness but they do lack the ability to enhance contrast.
Lens colors also comes in shades of amber. These are “my choice” which I consider a happy medium. They tone down brightness and will give contrast that is vital when stream and river characteristics include boulders and other structures. Take note of the side shields on the amber pair of glasses to the right. if the pair of optics you have chosen does not feature side protection, then i strongly recommend adding a pair which simply slide down the stems. They are made usually of a pliable plastic that will not add too much weight. Making this addition dampers your peripheral vision which will keep the angler more focused and will tire your eyes less.
Last but not the least, rose colored glasses are by far the best at sighting fish if the dynamics of the river are mostly part void of structures and water visibility is fairly clear.

http://www.defranksflies.com/polarized-sunglasses/