The effect of the trace element zinc on the change in the axial length and diopters and the variations of activities of superoxide dismutase (SOD) and nitric oxide synthase (NOS), and the content of NO in the retino pigmental epithelium choroid homogenate of the myopic eyes in form-sense-deprived chicks were studied. The results show that zinc can inhibit the elongation of axis oculi and increase the diopters in myopia. Meanwhile, the activities of SOD and NOS and the content of NO are significantly increased compared with the model group, indicating that zinc can be used to prevent and treat myopia to a certain extent.