As I write there is a hint of sunshine outside (it's 7.30 am in Nelson, New Zealand) and it looks like it’s going to be a glorious sunny day so I am going to need my new vintage style sunglasses that I purchased online for under $20.
 

Most sunglasses designs you see these days in the stores or online designs inspired by vintage designs from the past. So how does it work? Well, for manufacturers to avoid prosecution for deign theft they only need change a sunglass design by a mere 22%  and then they can produce them without any risk. The changes and tweaks can be anywhere on the frames and can include changes like thicker arms or wider frames.

In fact they can change the sunglass frames anywhere as long as it adds up to a total of 22% change. So from the original vintage design of say a Wayfarer , Aviator or Cat-Eye design there are have been so many tweaks and changes that these sunglasses have evolved. While still retaining some of their vintage roots and appearance they are not a copy of the original design and therefore the manufacturer or retailer cannot be touched by the law courts.
 

We now have manufacturers copying copies of vintage sunglasses so it’s hard to tell where the design originates. As far as I am concerned there are a number of vintage sunglasses designs that are still most prominent. Round frames i.e. like John Lennon style sunglasses, Wayfarers, Aviators that are unisex and Cat-Eye sunglasses which are most likely women's sunglasses. Anyway, I am just trying to give you some background as to where the vintage style sunglasses designs originate from these days and why you can buy something that looks like a designer pair of sunglasses for just $20 or less.