1. In both cases, the photopic luminosity curve is not shifted.

2. In optic neuritis the photopic ERG is normal.

3. This technique has proved more sensitive in semeiology than the photopic measure of visual acuity.

4. Photopic ERG induced responses similar in time, amplitude, and configuration to those of the dark-adapted ERG.

5. Testing revealed reduced visual acuity, adversely affected color discrimination, visual field defects, and a monophasic, “photopic” dark adaptation.

6. Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity

7. The central visual acuity in relation to illumination is normal in the scotopic range and does not exceed 0,2 in the photopic range.

8. The photopic visual field is characterized in the three subjects by a trouble of the spatial summations; a central scotoma has always been discovered.

9. Rods provide vision during dim light or night also known as scotopic vision, whereas Cones provide vision during day time or at bright light also known as photopic vision

10. The cases with complete congenital achromatopsia presented a uniform picture: the subjects affected were not able to distinguish colours at all; the ERG showed subnormal amplitudes of a- and b-waves and a flicker fusion frequency with a maximum of 10 cps according to the lack of photopic components; the course of dark adaptation was monophasic within the normal range or near to it.