The sunglass market is an enormous one. In 2012 alone, the American vision care market generated $34.54 billion, which doesn’t really come as a surprise. Sunglasses are among America’s favorite accessories. Unfortunately, it’s common practice to go through sunglasses like tissues, and many pairs simply wind up in landfills. Here, we’ll make the eco-friendly case for replacing sunglass lenses instead of replacing whole pairs of sunglasses. Here, we’ll talk about the three situations that definitely warrant sunglass lens replacement. Your Old Lenses Are Cracked or Broken Replacing sunglass lenses that have been cracked or broken is a very simple affair,…