Glasses, understood as the first pair of corrective spectacles, were invented in Italy sometime between 1268 and 1300. The invention is generally credited to Northern Italy in the late 13th century, with early models consisting of two magnifying glasses joined by a hinge and resting on the nose. These early eyeglasses were used primarily by monks and scholars for reading and became popular during the Renaissance. The first depiction of glasses in art appears in mid-14th century Italian frescoes. Before the invention of glasses as we know them, ancient Romans used glass to improve vision with tiny magnifying glasses and reading stones, shaped and polished lenses for vision correction were developed as early as the 9th century. The invention and production of glass lenses during the late 13th century in Murano, Italy, especially the grinding of convex lenses fitted into frames, marked a major breakthrough in eyewear. Glasses evolved over the centuries with innovations such as bifocals invented by Benjamin Franklin much later, but the original invention of the first wearable corrective lenses dates back to late 1200s Italy.