Exchange Threshold Colorimeter and Analytical Anomaloscope of Class I and Class II Subjects and Colour Defectives
Stephen R. Cobb · Perceptual and Motor Skills · 1981
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.