Objective:To investigate the protective effects of Shihu Yeguang Pill against light-induced photoreceptor degenerative changes. MethodsBALB/c mice were randomly divided into the normal control group, model group and Shihu Yeguang Pill treatment groups at different time points. The retinal light damage model was established in the model group and Shihu Yeguang Pill treatment groups by incandescent light at intensity of (10 000±10)lx lux for 30 min. The Shihu Yeguang Pill treatment groups were treated for continuous 7 days, and 24 hours before illumination the mice were received dark adaptation. The treatment groups were treated with decoction of Shihu Yeguang Pill by intragastric administration at volume of 200 μl immediately or 30 minutes before illumination. The normal control group and model group were treated with 0.9% NaCl solution at equivalent volume. 7 days after illumination, the optical coherence tomography (OCT) imaging was performed to detect the retinal structure of mice. The paraffin sections were made to perform the hematoxylin and eosin (HE) staining and immunohistochemical assessment of rhodopsin (RHO) and mid-wavelength sensitive cone opsin (M-opsin), in order to further clarify the changes of retinal morphology and patho logical changes of rod cells and cone cells.  Results:The retinal structures in the normal control group were intact, and the expressions and disposition of RHO and M-opsin were normal. Compared with the normal control group, the outer nuclear layer was obviously thinner in the model group, the structures of outer and inner segment layers of photoreceptor were disorganized and the expressions of RHO and M-opsin were remarkably decreased. Compared with the model group, the retinal structures were nearly intact and clear in Shihu Yeguang Pill treatment groups, and the expressions of RHO and M-opsin were increased.  Conclusion:Shihu Yeguang Pill shows significant protective effects against light-induced photoreceptor degenerative changes.