We present a procedure whereby the confocal laser scanning ophthalmoscope can be used to extract information about the three-dimensional structure of the central excavated area or the cup of the optic nerve head of the eye. The data are analyzed in terms of spherical harmonics. It is hypothesized that the shape of the cup of the optic nerve head for a normal eye can be parameterized by a specific set of spherical harmonic coefficients and is different from the set of coefficients describing a glaucomatous eye. The sets of coefficients are analyzed by using multivariate statistics and can in turn be used to classify new observations. Preliminary results indicate that there are significant differences in the coefficients and that the procedure might have potential as a diagnostic aid for the detection or the screening of glaucoma.