OPN4 and myopia: While the PLR induced by blue light at moderate to bright light intensities originates predominantly from the intrinsic response of melanopsin expressing retinal ganglion cells and thus bypasses any underlying outer-retinal or synaptic defects in myopic patients, such defects would have prompted an abnormal response to red light in patients with low and moderate myopia, as reported in patients with outer retinal diseases19,46.