The term 'eyeglass piece' can be summarized as a LENS, which is a four-letter word. A LENS is a curved piece of glass or plastic used in eyeglasses, cameras, and other optical devices to refract light and form an image. Lenses are typically made from transparent materials such as glass or plastic, and they come in a variety of shapes and sizes. They are used to correct vision, magnify objects, and focus light.