In a cohort of 50young ABCA4-associated retinopathy patients (age ≤ 10years), Lambertus and colleagues identified 10 individuals with visual functionloss in the absence of discernible fundus abnormalities at the time ofexamination and reported the onset of visual acuity decline from as early as 3years of age (Lambertus et al., 2015).Defects in color vision have also been reported in patients with early to nodetectable fundus changes (Bax et al.,2019a; Vandenbroucke et al.,2015). This evidence concerns the gene ABCA4 and retinal disorder.