Jivanta is a square glass with well-proportioned corners. As for durability, you have nothing to worry about because it is made of Acetate which is an extremely strong and impact resistant material. So while it improves your looks, it also protects your eyes from injuries. Accidents caused by frame fractures and friction are also avoided due to the frame structure. Square glasses are evenly proportioned with defined corners. The Acetate material is extremely tough, resilient, and impact-resistant. which can effectively prevent the damage to the eyes and the face caused by frame fracture and friction during sport activities. Recommended by Lensmart Online.