Frankly, I have never seen the need to spend the money dictated by "designer" glasses. The money you spend on them is not necessarily needed to get good quality, frankly.
I found that brown #3 lenses on good quality basic sunglasses works very well, and polaroid glasses should be avoided because of effects from plastic windows and poor visual cues near water.
This place has excellent glasses at good prices, and is the "secret" of many US pilots. They do excellent prescription word, including custom bi-focal segments at the top of the lens for reading overhead switches. I have no interest in this company, this is not a "plug" I am just a satisfied repeat customer:
Hidalgo's