I realize that you guys may laugh at what I am posting but I don't say anything unless I believe it to be true, especially about fishing. What you see perched on my hat in the picture below are the glasses I swear by. They were / are known as 'Fish Finders' and I suspect the older stock may be better than the new. I bought the pair in the picture at Tony's Salmon Shop in Pulaski NY. in 1994. These are the 10 dollar polarized glasses that come with the tag that until you look through the glasses has hidden fish on it. Sounds hokey I know but over the years I have been able to test them against the Orvis Marquis polarized, the Smith polarized, and I own 2 pair of Oakley glasses. The Fish Finders win hands down for locating trout and salmon in the water.
It has been my experience that while many 'cheap' items are exactly that, every now and then there is a gem to be had without paying an arm and leg. I keep them in a soft case and have managed to protect them from scratches and loss for 17 years now and yes, I have a second pair for backup should they ever be damaged. I like my Oakley's and you can find me driving my car, truck, motorcycle, bicycle, and snowmachine with a pair on my face & eyes. However when I am in that boat or wading a river the Fish Finders are always on my face. You would have to think that there must be some reason behind this.
As for worries about the 'cheap' lens failing to block UV radiation and my eyes being fried, I would think that I would have noticed something by now. As for where to find them?? You will have to just keep an eye out for them in tackle shops. In my opinion these were the norm for fishing before all of the people in marketing convinced the fly fishing public that every piece of gear has to cost hundreds of dollars or you will have less than successful results. I am often amazed at how willingly we as consumers are willing to accept the rational of 'more means better' this can be true but it should not be the chief decision making factor when you shop. Think or do as you chose but those cheap glasses will find my fish again this year, I have no doubt. I hope you can find a pair of these gathering dust in a shop somewhere and get them to try.