From Crb2 cKO, Crb1+/−Crb2 cKO and Crb1Crb2 cKO retina studies, the severity of the retinal disease is inversely proportional to the amount of CRB1 and CRB2 proteins which seemed to be critical for the development of the retina. This evidence concerns the gene CRB2 and Abnormal retinal morphology.