Visitors try a smart medical system during the 16th Optics Valley of China International Optoelectronic Exposition and Forum at the China Optics Valley Convention and Exhibition Center in Wuhan, capital of central China's Hubei Province, Nov. 13, 2019. The three-day Optics Valley of China International Optoelectronic Exposition and Forum kicked off here on Wednesday. (Xinhua/Xiong Qi)