It was observed that the animal models of retinal degeneration (Rd10 and Opn4−/− × Rd10) showed serious damage to the outer layers of the retina (outer segments of the photoreceptors and outer nuclear layer), as they lacked labeling compared to non-degenerate models (C57BL/6J and y Opn4−/−) (Figure 7). This evidence concerns the gene OPN4 and retinal degeneration.