Researchers have developed a dual-gene therapy approach to treat Usher syndrome type 1F, a rare condition causing deafness and progressive blindness. By splitting the large PCDH15 gene into two halves, delivering them via adeno-associated viruses, and reassembling them in cells, the therapy restored hearing and balance in mice. Tests in human retinal organoids and primate retinas showed increased levels of protocadherin-15 in light-sensing cells, offering hope for vision preservation.