CACNA1F and congenital stationary night blindness 2A: Congenital stationary night blindness 2A (CSNB2A) is a genetic retinal disorder characterized by poor visual acuity, nystagmus, strabismus, and other signs of retinal dysfunction resulting from mutations in Cacna1f—the gene coding for the pore-forming subunit of the calcium channel CaV1.4.