Which type of bridge is a clear plastic saddle-type attached to a metal frame without nosepad arms?

The correct answer is that the type of bridge described is a comfort bridge. A comfort bridge is specifically designed with the intention of increasing the overall comfort for the wearer. This type of bridge features a clear plastic saddle that conforms closely to the shape of the nose, distributing weight evenly without the use of traditional nose pads. This design helps to reduce pressure points and provides a stable fit.

In contrast, saddle bridges do feature a similar saddle-like design but are not necessarily made from clear plastic or intended specifically for enhanced comfort in the same way a comfort bridge is. A keyhole bridge is characterized by a notch that allows the glasses to sit lower on the nose and may include nose pads or arms. The strap bridge incorporates additional elements like straps that go around the back of the head, further differing from the characteristics of a comfort bridge. Understanding these distinctions highlights the unique attributes of the comfort bridge and why it fits the description in the question.