If you talk with any
shop rats distinguished fly shop employees, they’ll tell you how often people ask about sunglasses. Are they polarized? What color should I buy? Why the hell do they cost so much?!?!?!
Head over to Midcurrent for a primer on sunglasses. The author only mentions Smiths in the article, but there are many good options out there. Regardless of what you choose (Costa and Smith for me), learn a bit more about what you need and invest in a good pair. You’ll be glad you did.