During the 19th century, as more doctors started to specialise in eye disease alone, increasingly complicated operations were devised. The introduction of anaesthesia in 1846 and the adoption of antiseptic techniques by the 1880s, increased the number and complexity of the eye operations that were performed. Artificial eyes have been made since Renaissance times, when Venetian glassmakers began to produce glass eyes. The art flourished in France and Germany in the 19th century. After World War II, plastic superseded glass as the favoured material for artificial eyes.