This study aimed to estimate the optimal light conditions for indoor cultivation of juvenile tiger puffer (Takifugu rubripes), The juvenile fish were exposed to five intensities of green light (G1:300 mW/m2, G2:500 mW/m2, G3:750 mW/m2, G4:1 000 mW/m2 and G5:1 500 mW/m2), white light (W) and dark (D) for 60 days. At the end of the experiment, the retinal structure of the juvenile fish was observed, and measurements were taken for retinal thickness, expression of visual protein genes, and changes in antioxidant enzyme activity. The results showed that different intensities of green light had no significant effect on the retinal structure of juvenile fish. Different degrees of melanin migration occurred in the retina of all treatment groups. Melanin granules were more aggregated in the G1 and D groups, while in the G4 and G5 treatment groups, the density of melanin granules was relatively large. The total retinal thickness (TT)decreased with the increase of green light intensity. The ratio of the thickness of each retinal layer to the total thickness was further analyzed. The results showed that the changes in retinal thickness showed different trends among different regions, with the G3 group having the highest proportion of photoreceptor layer (PRos/is/TT) (P<0.05), and the proportion of outer plexiform layer (OPL/TT) was significantly higher than those in other groups except G1 (P<0.05). The proportion of outer nuclear layer (ONL/TT) of juvenile fish in the G2 and G3 groups was significantly higher than that in the G1 and G4 groups (P<0.05). There was no significant difference in the proportion of pigment epithelium (RPE/TT) and ganglion cell layer (GCL/TT) among different treatment groups (P>0.05). Regarding the expression of opsins genes, Rod opsin expression was highest in groups exposed to white light (W)and dark conditions (D)(P<0.05). SWS2 expression in the G3 group was the highest (P<0.05). The expression of Opsin3 was the highest in the W group and the G5 group (P<0.05). For antioxidant enzymes, the activities of Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione Peroxidase (GPX) in the green light treatment groups increased regularly with the increase of light intensity, and there was no extreme decrease. In view of the effects of different light intensities on retinal thickness and oxidative stress in eye tissues of juvenile tiger puffer in this study, it is recommended to use a white-colored cultivation substrate and green light in indoor cultivation environments. Additionally, it is advised to control the light intensity within the range of 500 to 750 mW/m2.