The similar clinical presentation between familial achromatopsia in humans and bovine recessive day-blindness led to the hypothesis that a protein-changing variant within CNGA3, CNGB3, GNAT2, ATF6, PDE6C, and PDE6H would be associated with achromatopsia of Original Braunvieh calves. Here, CNGA3 is linked to achromatopsia.