Patients with inherited eye diseases waiting for a free diagnosis at the Beijing Genomics Institute's Youkang outpatient department in Shenzhen on Aug 18. Zheng Yanling (left) brought her 12-year-old son Ke Zewei (the second from left), who was blind through retina dysplasia, there. She was hoping the experts could find out whether the boy would one day be able to see and how to prevent passing the disease to the next generation. Huang Yuli / China Daily