Several retinal degenerative diseases cause vision loss and retinal cell death. Currently, people face prolonged exposure to digital screens, rendering vision protection from light exposure a critical topic. In this study, we designed a complex lutein formula (CLF) by combining several natural compounds: Calendula officinalis, Lycium barbarum, Vaccinium myrtillus, Cassia obtusifolia, and Rhodiola rosea. In addition, we evaluated the protective effects of the formula on retinal functions in an animal model for light-induced retinal degeneration. We employed electroretinography to analyse retinal function, and conducted a histological examination of the morphological changes in the retina treated under various conditions. We revealed that the retinal function in animals exposed to light for 7 days decreased significantly; however, the retinal function of animals that had received the CLF exhibited superior performance, despite light exposure. In addition, a greater portion of the outer nuclear layer (ONL) (i.e. the nuclei of photoreceptors) in these animals was preserved compared with the animals that had not received the formula after 7 days of light exposure. These results revealed that our dietary CLF supplement attenuated retinal function loss resulting from long-term light exposure.