These are Ralph made sunglasses and they are about 13 to 14 years old.  
I originally sold them to Doris way back in the very very first location on Memorial. 
She has taken care of them so well that I've made prescription changes and updates about 4 times during their lifetime.  

She came to me just last week and asked if they were in good enough condition for them to withstand another prescription change.   
After quickly looking at them, you can usually see that these things are going to continue to last way beyond what most sunglasses even last.
Especially in Houston weather, because it's always so so hot and sunglasses here end up taking lots and lots of abuse.
Great quality.  

Over the years, I've also changed out not just the lenses, but the nose pads and also these screws and the matching nuts.
The screws and the nuts, they tend to wear off and get stripped and so that is when they have to be changed.  
And, i do it sometimes even more often than a prescription change because they do have to be tightened up.  
This is, even though, it has a frame, you can see the frame right there on the back. 
It's really strictly just to keep it a little more stable and give it more stability, 
but in essence it's considered a 3 piece because you do have to perforate the lenses and that is how the lenses are held in place with the screws and the nuts. These sunglasses are amazing.  They've been around for a long time. 

It's important to know that the person who is picking out the sunglasses and the eyeglasses who basically curating the collections within the store.
That person is going to have to know how great of a quality the inventory is because of the experience they've had with either the different brands or even the manufacturing houses that make these products.  
Sometimes the company whose brand the frame wears on the side is not really who is making the eyeglasses.  
Somebody is going to have to know who is that is manufacturing, that way they can determine and predict how great the quality of those frames are going to be and how long they're going to last well in the future.  
As long as a person takes good care of them, you can really predict how long they're going to last.