A nucleic acid trans-splicing molecule is provided that can replace an exon in a targeted mammalian ocular gene carrying a defect or mutation causing an ocular disease with an exon having the naturally-occurring sequence without the defect or mutation. A method of treating an ocular disease, e.g., Stargardts Disease, caused by a defect or mutation in a target gene, e.g., ABCA4 comprising: administering to the ocular cells of a subject having an ocular disease a composition comprising a recombinant AAV comprising a nucleic acid trans-splicing molecule as described above.