Abnormal amplitude of dark-adapted bright flash electroretinogram Supernormal dark-adapted bright flash electroretinogram b-wave The S (short wavelength) cones respond to blue wavelengths. This feature is defined by a super-normal photoreceptor component elicited by short-wavelength lights and a subnormal photoreceptor component elicited by long-wavelength lights. The super-normal component derives from S cones. Individuals with pathogenic variation in NR2E3, which causes enhanced S cone syndrome, may have an increased ratio of S cones to other cones. Relatively enhanced S-cone responses The b-wave amplitude exceeding the upper limit of normal under scotopic (dark-adapted) conditions with high-intensity stimulation. UMLS:C4072974