Suppression of TH signaling by antithyroid treatment, inhibition of Dio2, overexpression of Dio3, or deletion of TH receptor reduces cone degeneration in mouse models of LCA, cone dystrophy/achromatopsia (Ma et al., 2014; Yang et al., 2016), and a chemically induced mouse model of AMD (Ma et al., 2020, 2022). Here, TH is linked to age-related macular degeneration.