1. The most common type of Color blindness makes it hard to tell the difference b etwe en red and green. There are 4 types of red-green Color blindness: Deuteranomaly is the most common type of red-green Color blindness

2. Normal Trichromats Congenital Red-Green-Defects Protanopia Deuteranopia Protanomaly Deuteranomaly Acquired Tritan-defects (for instance infantile dominant optic atrophy) Acquired Tritanopia Acquired Tritanomaly Congenital Tritan-Defects Tritanopia Tritanomaly Congenital Achromatopsia with Scotopic Vλ-curve The conditions for illumination and for the examination-procedure are equal to those of the Nagel-Anomaloscope.