There is a specific Costa sunglass model I like but it's only offered in size Large ... and I need a medium frame.  Does Costa vary the size of their models year over year, or is it pretty much one model/one size?

I've only seen a model in one size.

One model, one size. I suggest searching their site by size. They often have frame styles that are similar (not exactly the same though) in the different sizes. As a guy that wears medium/small frames for sunglasses, I feel your pain. It can be a bear to find a pair you like that doesn't look ridiculous. I ended up going with the Brines. Great fit for my face and don't make you look ridiculous like half of the models do. 

Is there a certain time of year that Costa releases new models?  I have a new prescription but I guess I don't have to buy new frames right aways...

15 hours ago, FryDog62 said:

There is a specific Costa sunglass model I like but it's only offered in size Large ... and I need a medium frame.  Does Costa vary the size of their models year over year, or is it pretty much one model/one size?

 

You want either the fathom or the brine. I have a smallish head and both of those work well for me.

I like the crystal and black combo on the Tuna Alley... unfortunately they don't make it in a Medium. 

 

...don't think any of the Medium frames have the crystal color --

I have the Brine and the Jose and have a medium sized head.  Most large glasses are a little too big on me.  Both of those models are great as are the Fantails.  Best of luck with the new sunglasses.

Fantails in crystal color would be a purchase for me too...