The present application provides materials and methods for treating a patient with autosomal dominant CORD, both ex vivo and in vivo; materials and methods for editing a GUCY2D gene in a human cell; and materials and methods for editing a R838H, R838C, or R838S mutation in a GUCY2D gene in a human cell. The present application also provides one or more gRNAs or sgRNAs for editing a GUCY2D gene; one or more gRNAs or sgRNAs for editing a R838H, R838C, or R838S mutation in a GUCY2D gene; and a therapeutic comprising at least one or more gRNAs or sgRNAs for editing a R838H, R838C, or R838S mutation in a GUCY2D gene. The present application provides a therapeutic for treating a patient with autosomal dominant CORD. The present application also provides a kit for treating a patient with autosomal dominant CORD. In addition, the present application provides a self-inactivating CRISPR-Cas system.