Gresso glasses are incredibly light and totally unbreakable. You shouldn't worry about durability anymore.
Lenses: Carl Zeiss
Weight: 19 g
The best I have ever worn. I spend a great deal outside as an engineer and these work great at keeping the sun out of my eyes as well as allowing me the ability to read the digital read outs on my instruments. The frames are super lightweight and durable while very flexable.