I took the click bait...
 

And glad I did...I'm sure you saw the Facebook ad.Costa sunglasses $249.00 for $15.99 or 70%off
I told myself a while back I was done with cheap sunglasses because the lens scratches so easy and in the long run you spend more money. So I'm used to spending around $50 for a good lens that won't scratch easy. So I figured I would try the ad, it had Costa del mars
Name on it. So I bought 3 pair for $47 the same price I spend For one of my other brands. I figured if they scratch easy ill just toss and move on to another pair.
I have to say I'm highly impressed, time will tell how long the lens will last with out scratching. Definitely not money wasted.
I bought two blue off shore and one green inshore

-----------> o
 

------> o

I can't be sure about the quality, but I could only imagine that the lens may not be that great. If you're concerned about protecting your eyes, I'd opt with a legit sunglass in your normal $50 range that will provide proper UV protection for your eyes. I can't imagine a $16 knockoff will give you that, but who knows.

They look good though!

Gotta be a Chinese knock off or that is CRAZY!

Costas are good glasses. That price is insane.

I googled uv protection....
 

And it said in hi lighted that all polarized sunglasses are 100%uv protection, thin I clicked on polarized and it took me to Costa del Mar website,where I bought the sunglasses. Definitely contracted out...:D

In case you didn't no.....
 

You can Google YouTube videos on how to test sunglasses, stickers mean nothing, for 100% uv protection it's a simple test yay or nay... you can do it with a $7 black light flashlight and a dollar bill,but a blacklight poster works better for the test. I ordered the black light on Amazon I will give you the results, I'm laughing because after watching some YouTube videos some $5 sunglasses had %100 uv protection and more expensive ones failed....stay tuned I will give you the results of my cheap sun glasses from Costa, when I get my blacklight flashlight :cool:

Thank you for your post and the information provided.

My black light flashlight test results
 

The first picture is with out sun glasses just black light .
The other are my new Costa knock offs and my old $50 pair I bought at Rei. I think both sun glasses pass but I think my old pair were a little darker with black light shinning through the len. If I had children I would definitely be testing the sunglasses I put on them, uv rays can cause eye cancer.

My old pair of $50 sunglasses I bought at REI
 

Even tho they have several coats of over spray paint the lens are still good enough to use no scratches. I repaired broken flippers with fishing tackle. Drilled two small holes in ends and used steel leader lead crimps swivels shrink tubing and velcro, turned them into goggles. They slide up nice on your forehead under your hat.

After posting on another website...
 

I got some negative feedback on my uv sunglasses test.
So I had a dr app, after that I took my cheap Costa knockoffs to vision care dr and ask him if he could check the uv rating on my cheap sunglasses. Good news and bad news. The bad news my sunglasses had some uv protection but he couldn't give me a percentage, and he said they were not polarized. I ordered fishing glasses what a joke. So now I'm going to find out if polarized means 100% uv protection and if there's different levels of polarization. I will not buy these sunglasses again but I will put them to good use. The good news is this test is legitimate and a uv flashlight and a blacklight flashlight are the same. The dr said if the blacklight shine through the lens your not getting full protection . So now when I buy my next pair I will be testing them first with my blacklight.

If you put the glasses on and cars look like theyre changing colors through the tint on your windows, or if the clouds in your mirrors look purple and blue, they are polarized.

The first time i wore polarized sunglasses I was blown away at the way regular things look through them, as I mentioned above, cars look like they are changing colors as they pass you/you pass them, you can see the spots/patterns on auto glass where the tint is uneven, etc. If you have an older phone the digitizer may have a polarizer that looks crazy through the glasses.

I can not use polarized in my 4Runner if I want to see my GPS screen.

Testing for polarization is easy if you have two sets of glasses. Hold one in front of the other and you should be able to see through the lenses, pretty much like it was a single set. Now turn one set to where it is 90 degrees to the other. You should not be able to see through at all

This was kind of my point the whole time. Why not just spend the $50 on glasses that you know are legit. Why take a chance purchasing from websites clearly selling knockoffs they wouldn't wear themselves?

It is what it is....
 

With no regrets