How to choose glasses: Plastic spectacle frames vs. metal

I would add a third choice which is rimless eyewear like silhouette or kawasaki or some other brand. Silhouettes are very lite, always made out of titanium and very hard to brake. They would usually last for at least 4-6 years and if your prescription changes, most of opticians can change the shape of your lenses, so you can have a different look whenever you change your prescription.