This definition can vary from company to company, but we use a couple of rules of thumb to determine what constitutes ‘round’ sunglasses. First, the aspect ratio (the ratio of the width and height) should be closer to 1:1 than 1:2. Second, and maybe obviously, the silhouette of the frames from the front should have few or no defined corners.
Round sunglasses are suited to most men’s face shapes, including oblong, heart, diamond, and especially square. Round faces should generally avoid round sunglasses, as the reinforcement of soft shapes may make features appear less defined and overly ‘soft’; if you have a round face, consider looking at more angular styles with a wider aspect ratio.
In most cases, the durability of a pair of sunglasses depends more on its material than its shape. Choosing the right material for your uses and properly caring for and maintaining your frames will determine the lifespan of your product much more than the frame shape will. That being said—by their nature, round sunglasses do not have protruding corners or other features that will easily catch or break.
Since their comeback in the early 2010s, round sunglasses certainly aren’t “out of style”, but have rather transcended their place as a fad and become a part of the pantheon of standard sunglasses shapes. It seems, for now, that round sunglasses are here to stay as an option to consider regardless of passing trends.