OPN3 and myopia: Linne et al. (2023) created a retina-specific Opn3 knockout and found that the mice did not have myopia, suggesting that germline Opn3, and not retinal Opn3, is responsible for the phenotype observed in Opn3−/− mice. The data also showed that both germline and retina-specific Opn3 null mice had similar responses to LIM (Linne et al. 2023). Overall, these authors concluded that nonretinal Opn3 influences refractive development and the response to LIM.