Causes of moderate to severe visual impairment and blindness in population aged 50 years or more in rural Shandong province

Li Y, Bi HS, Wang LH, Wang T, Yang SY, Liu LP, Zhou CC. Causes of moderate to severe visual impairment and blindness in population aged 50 years or more in rural Shandong province. Chin J Ophthalmol. 2013; 49(2): 144-50.