Which two types of bridge designs can be found on a spectacle frame?

The types of bridge designs found on a spectacle frame are keyhole and saddle. The keyhole bridge has a shape that resembles a keyhole, allowing for a comfortable fit on the nose while providing a secure hold for the eyewear, making it a popular choice for many frame designs. The saddle bridge design features a soft curve that rests comfortably on the nose, distributing the weight evenly and enhancing comfort for long-term wear.

Other designs, such as cat-eye and round, refer more to the shape of the lenses or overall frame rather than the bridge style specifically. While flat and curved could describe the overall profile of a frame, and wide and narrow might refer to the dimensions of the frame itself, they do not accurately depict types of bridge designs. Thus, keyhole and saddle are the correct choices for describing bridge types in eyewear, as they directly relate to how the frames interact with the wearer's nose and enhance overall comfort.