Abstract: To systematically clarify the mechanism underlying the effects of nocturnal artificial light on the visual system and the physiological response patterns of Sebastes schlegelii, a cold-temperate benthic reef fish. Juvenile S. schlegelii with an initial body weight of (34.22±4.77) g were used as experimental animals. Five nocturnal light treatment groups (red light, green light, blue light, white light, and flashing light) and a dark control group without nocturnal light were set up. All groups were exposed to natural daylight during the daytime (8:30–20:30), and a 7-day culture experiment was conducted. Samples were collected at two key time points (8:00 and 20:00) to measure antioxidant indicators malondialdehyde (MDA), lipid peroxide (LPO), superoxide dismutase (SOD), catalase (CAT), etc., neuroendocrine factors (cortisol, melatonin), and the relative expression levels of functionally related genes (apoptosis pathway genes, opsin genes) in eye tissues, so as to comprehensively analyze the biological effects of different light spectra under nocturnal illumination. At 8:00, the contents of MDA and LPO in the eye tissues of the red, blue, and white light groups were significantly higher than those in the control group (P < 0.05). Among them, the activities of SOD and CAT were significantly upregulated in the red light group but significantly downregulated in the blue and white light groups. At 20:00, no significant differences were observed in LPO content or SOD and CAT activities among all treatment groups (P > 0.05), whereas MDA content in the red, blue, and white light groups remained significantly higher than that in the control group. GPX4 activity showed no significant differences between the two time points in all treatment groups. The expression levels of apoptosis-related genes such as foxo3, tp53, and bcl2 were significantly upregulated in the red and white light groups. The green light group significantly reduced MDA and LPO concentrations and enhanced SOD and CAT activities at both sampling time points, exerting a clear inhibitory effect on oxidative damage. The cortisol level in the blue light group was significantly lower than that in other groups, while the melatonin level was significantly higher than that in the control and other treatment groups. Flashing light did not aggravate oxidative stress or upregulate apoptosis-related genes, showing no significant adverse effects on the visual system of S. schlegelii. The opsin gene sws2 shows an expression pattern of being upregulated during the day and downregulated at night, while the expression of rh1 and rh2 genes fluctuates abnormally due to the interference of nocturnal light. This study confirms that nocturnal red, blue, and white light can induce oxidative stress in the visual system of S. schlegelii and bidirectionally regulate the expression of apoptosis-related genes. Green light exerts a protective regulatory effect, while flashing light has no significant negative impact. The results provide an important scientific basis for the optimal regulation of nocturnal light in the aquaculture environment of S. schlegelii and the ecological prevention and control of light pollution in coastal waters.