title: Exchange threshold colorimeter and analytical anomaloscope of class I and class II subjects and colour defectives.
abstract: The spectral absorption curve of 'red' cones erytholabe and the 'green' cones chlorolabe are examined by these techniques. Evidence is elicited for a fourth photopic response peaking at approximately 570 nm.
mesh_terms: D003118:Color Perception / Q000502:physiology; D003119:Color Perception Tests / Q000295:instrumentation*; D003117:Color Vision Defects / Q000175:diagnosis*; D006801:Humans; D010786:Photoreceptor Cells / Q000502:physiology; D012168:Retinal Pigments / Q000502:physiology; D012684:Sensory Thresholds
chemical_list: D012168:Retinal Pigments