Clinical visual acuity assessment is performed with maximum optotype contrast within a very narrow luminance range (80-320 cd/m²), barely reflecting patients’ visual capabilities in daily life. However, visual acuity alone does not adequately assess the visual performance in retinal disorders, especially in those causing an increased glare-sensitivity like achromatopsia.

For a more realistic assessment of patients’ visual performance under everyday life conditions with different contrast levels (C) and ambient luminance (AL), we develop a novel visual acuity score, called VA-CAL.