Codon optimized nucleic acid sequences for the long form and short form of RdCVF are provided, as well as recombinant viral vectors, such as AAV, expression cassettes, proviral plasmids or other plasmids containing the codon optimized sequences. Recombinant vectors are provided that express the codon optimized RdCVFL and RdCVF individually, or express two copies of a codon optimized RdCVF or RdCVFL nucleic acid sequence, or both RdCVFL and RdCVF in a single vector or virus. Compositions containing these codon optimized sequences are useful in methods for treating, retarding or halting certain blinding diseases resulting from the absence or inappropriate expression of RdCVF and RdCVFL.