EYS and retinitis pigmentosa 1: In order to study the long-term effect of exon skipping as a future treatment option for EYS-associated RP, we employed the CRISPR/Cas9 system to generate stable zebrafish mutants from which the genomic region that encompasses the orthologous exons 37-41 of human EYS (eys exons 40-44) was specifically excised.