Up until two years ago, I was wearing a pair of Costa Zanes with glass lenses... I had that pair for a pretty long time, wore them so much, the retainer cable I had finally broke... Well, as luck would have it, they fell of my face, hit the water while lipping one of the biggest Florida Strain Largemouths I had ever caught, and I couldn’t grab them before they sank to the bottom of the lake (was Carolina rigging in 27’ of water so, trying to fish them out wasn’t a possibility)... After losing that pair, I was so frustrated, I decided to never again buy expensive sunglasses; because I always seem lose them (someway, somehow)... However, after using cheap sunglasses for right at two years, I found these... I purchased the 580p lenses for two reasons mainly... One, they are more affordable and two, I’ve never wore the Brine (not sure of the fit)... I actually like the fit better than the Zanes (they are a little smaller and lighter), and couldn’t be more pleased with the lenses... They actually perform better than the glass lenses I had in my old pair (they were the 400p lenses), and make this pair even lighter... So my recommendation, if you are the type of person that spends any significant amount of time outdoors, investing ($100 - $250), in a pair of these is definitely worth it... If you’ve never owned a pair of Costa Del Mar sunglasses, you don’t know what you may be missing and if you have owned a pair; you know it’s pretty much impossible to be satisfied with a cheap pair of sunglasses... At this price, I believe these are the perfect pair to try out... Remember, they are a little bit smaller than pairs such a the Zanes or Fathoms by Costa but, the perfect fit it you want a pair of sunglasses that are snug and so light, you can forget your wearing them at all (I’ve walked into my office building and all the way to my desk more than once before I realized I had them on)... Just my $0.02...