Design: These patients and their families will undergo detailed ophthalmological examinations and, where indicated, additional non-investigational examinations to characterize disease in their families and determine their affectation status. A blood sample will be collected from each individual for isolation of DNA and in some individual s biochemical studies or for lymphoblastoid transformation to establish a renewable source of DNA. Linkage analysis, physical mapping, and mutational screening will be carried out to identify the specific the gene and the mutations in it that are associated with myopia in this family. If necessary, the gene product or blood sample will be characterized biochemically. The study will enroll subjects at the NEI and at collaborating centers including the Zhongshan Ophthalmic Center of Sun Yat-Sen University, Guangzhou, China.