These interactions also have consequences for the development of vision tests designed to detect subtle visual contrast loss in disease when there is melanopsin dysfunction (Chougule et al., 2019; Feigl et al., 2011, 2012; Joyce et al., 2018; La Morgia et al., 2016; Maynard et al., 2015; Munch et al., 2015; Najjar et al., 2018; Park et al., 2017) and thus an associated change in its support of rod-mediated and cone-mediated vision in retinal disease. This evidence concerns the gene OPN4 and Abnormal retinal morphology.