Many people choose metal frames because they have a subtler look, are smaller, and are lighter in weight. Some people think that metal frames are cooler to wear (as in temperature) than plastic frames because they allow more air to flow to your cheeks and eyes, and some of the metals being used to manufacture them are extremely durable. Plastic frames are thicker, and they have a much bolder look. So if you’re looking for a pair of glasses that make a statement, plastic may be a better choice.