Though I may have missed it in skimming over the numerous posts, the key difference between inexpensive and quality eye wear is the the protection provided to a fisherman's most important sense, their vision. A lifetime of unrelenting, reflective light can cause various vision problems. Though cataracts can be caused by some medical conditions, ultraviolet radiation is also thought to be one possible contributing factor in their formation.
According to an an article at WebMD, "...Ultraviolet (UVA or UVB) radiation is invisible but these rays are the same culprits in causing sunburn, skin aging, and skin cancers as well as cataracts and macular degeneration (an aging-related disorder of the retina). UVB poses a particular danger for cataracts. The eyes are normally protected from the sun by eyelids and the structure of the face (overhanging brows, prominent cheekbones, and the nose). Long-term exposure to even low levels of UVB radiation, however, can eventually cause changes in the lens, including pigment changes, that contribute to cataract development."
Bottom line, if you want to see what your doing out there for a lifetime, always protect your eyes.
Tight Lines, Speynut