Table 2

Summary of psychophysical findings

Case	Age (years)	HRR	D-15	Mollon-Reffin “minimal” test	Anomaloscope	Cambridge computerised colour test
1A	8	All correct	Normal	Slight elevation of discrimination threshold along deutan axis	Normal range	Slight elevation of discrimination thresholds along all three colour axes
2A	6	All correct	Normal	Slight elevation of discrimination threshold along deutan axis	Normal range	Slight elevation of discrimination thresholds along all three colour axes
3B	8	All correct		Slight elevation of discrimination thresholds along protan and deutan axes	Normal range	Slight elevation of discrimination thresholds along all three colour axes
4C	14	All correct	Normal	Normal	Normal range	Within the normal range along all three axes
5C	6	2 plates incorrect	2 minor transpositions	Normal	Normal range	Slight elevation of discrimination thresholds along all three colour axes
6D	8	1 plate incorrect	2 minor transpositions	Normal	Normal range	Slight elevation of discrimination thresholds along all three colour axes