Objective:To investigate the protective effects of Picrorhiza scrophulariiflora (PS) on photoreceptor cell degeneration induced by light injury. MethodsBALB/c mice were randomly divided into five groups: normal control group (No Light), light damage group (Light_Vehicle), low-dose PS treatment group (Light_HHL_L), medium-dose PS treatment group (Light_HHL_M) and high-dose PS treatment group (Light_HHL_H), with 6 mice in each group. The normal control group and the light damage group were gavaged with 200 μL pure water solution per 20 g of murine body mass. The low (167 mg/kg), medium (500 mg/kg) and high (1.5 g/kg) dose groups of PS were received decoction of PS with 200 μL per 20 g of murine body mass. The mice were treated for continuous 7 days. All mice began to receive dark adaptation on the 4th day. On the 7th day, the PS treatment groups and light damage group were exposed to bright light for 30 min after intragastric administration. Seven days after illumination, the optical coherence tomography (OCT) imaging was performed to detect the thickness of retinal outer retinal nucleus layer (ONL) in vivo. The hematoxylin-eosin (HE) staining was used to observe the changes of retinal morphology and structure. Electroretinogram (ERG) was used to analyze the amplitude changes of a wave and b wave, which reflected the retinal function. The immunohistochemical assessment of Rhodopsin and M-opsin protein were performed to observe the rod and cone cells. Retinal apoptosis cells were observed in situ by TUNEL assay.  Results:The retinal morphology and structure were intact and the cell nuclei were neatly arranged in the normal control group, and the amplitudes of a wave and b wave in scotopic ERG increased with stimulus intensity, and the expressions of rhodopsin and m-opsin were normal. No apoptotic cells were found in all layers of the retina. Compared with the normal control group, the retinal structure was significantly damaged and the thickness of retinal ONL was significantly thinner (P＜0.01) in the light damage group.The cell nuclei in ONL were loosely arranged and disordered, and the amplitudes of a and b waves of scotopic ERG were significantly reduced (P＜0.05).The expression of rhodopsin and M-opsin decreased significantly. A large number of apoptotic cells were observed in ONL. Compared with the light damage group, the retinal morphology and structure remained intact and the ONL nuclei were arranged neatly in the high dose PS treatment group. PS could effectively inhibit the thinning of ONL thickness (P＜0.01) and the decrease of a wave and b wave (P＜0.05).The expressions of Rhodopsin and M-opsin were significantly increased in the PS treatment groups and few apoptotic cells were observed in ONL. ConslusionThe apoptosis of photoreceptor cells induced by light injury is significantly inhibited by the intervention of PS, and PS has a significant protective effect on the retinal morphological structure and visual function in bright light-damaged mice.