RGS9 and oligocone trichromacy: Electroretinograms according to the protocol recommendations by the International Society for Clinical Electrophysiology of Vision (ISCEV)8, 9 also do not allow for the distinction to be made between RGS9/R9AP-associated retinopathy and oligocone trichromacy, with more comprehensive electroretinograms than those mandated by the ISCEV in the electroretinogram standard document being needed.