However, blocking Ca2+ currents mediated by Cav1.4 might be counterproductive for restoring vision because Cav1.4-KO mice are functionally blind28, and humans with mutations in the CACNA1F gene encoding Cav1.4 channels suffer from congenital stationary night blindness type 2 (OMIM 300071, for review29). This evidence concerns the gene CACNA1F and congenital stationary night blindness 2A.