There are three types of frames: Full Frame Full frames completely outline the lens. They are the most durable frame type, and we recommend them for thick lenses. Semi-rimless Frame Semi-rimless frames cover the top portion of the lens. They are lighter and more comfortable but expose the lens to chips and cracks. Rimless Frame Rimless frames provide the largest field of vision and are the most lightweight option. However, they are more delicate than other frames.