A collaborative research initiative between French and Spanish scientists has shown that copy number variations (CNV), particularly mid-size genomic rearrangements in the EYS gene, may be a common occurrence in recessive retinitis pigmentosa (RP). The finding represents the first report of a CNV screening of the EYS gene (a recently discovered gene in the RP25 locus for recessive RP) and the results demonstrate that such genomic alterations may be responsible for the phenotype of up to 4% of families with no reported mutations. Introduction of a genetic test based on the research may represent a cost-effective strategy for application in the future clinical management of recessive RP associated with the EYS gene.