The Vingrys Analysis performs a vector analysis of the data and provides a series of indices describing the orientation, magnitude and polarity of the data.
The Confusion index (C-index) describes the severity of a color loss. A perfect arrangement of caps will give a C-index of 1.0.
The Scatter index (S-index) quantifies the specificity (polarity or randomness) of a cap arrangement. A perfect arrangement of caps gives an S-index of 1.28.
The Angle identifies the orientation of the cap arrangement.
The results of the Vingrys analysis are used to determine a provisional diagnosis.
Reference
For more information on the derivation and application of this analysis, see:
Vingrys, A.J. and King-Smith, P.E. (1988) A quantitative scoring technique for panel tests of color vision. Investigative Ophthalmology and Visual Science, Vol 29, No 1, pp 50-63.