RGS9 and Photophobia: However, patients report slow visual adaptation to changes in illumination, in both dark- and light-adapted states.3, 4, 5 These symptoms are shared with oligocone trichromacy, another cone dysfunction syndrome characterized by normal fundus appearance, normal or near-normal color vision, reduced visual acuity from infancy, and mild photophobia.5, 6, 7 Unlike RGS9/R9AP-associated retinopathy, the underlying molecular genetic basis of oligocone trichromacy remains uncertain.