This display shows the congruence (symmetry) between right and left visual field. Both visual fields are superimposed without mirroring (homonymous). At each point the difference RIGHT-LEFT field is calculated
Right image: difference value as number. Positive number = value (defect depth) better on the right eye
Left image: compound of 2 Color Defect Maps from the right and left eye. Dependent on the difference, various geometrical patterns are shown:
VERTICAL stripes: difference positive, values better on the right and worse on the left eye
 
HORIZONTAL stripes: difference negative, values worse on the right eye
UNIFORM areas: mimimal  difference between right and left, defect depth in the same color shade class
 
Only matching points are superimposed. In  case of asymmetric patterns, e.g.  Octopus G1, some points are omitted