In an ophthalmic instrument that directs a fluid pulse at a cornea to cause reversible deformation of the cornea and monitors the corneal deformation to generate a deformation signal, the shape of the deformation signal is analyzed with respect to deformation signal data from a statistical population of eyes to calculate a deformation signal score indicating a degree of probability that the deformation signal corresponds in shape to a normal deformation signal for normal eyes in the population. In calculating the deformation signal score, significant geometrical signal parameters are calculated and combined. The deformation signal score may be used as a basis to keep or discard intraocular pressure measurements in a non-contact tonometer, and/or as a basis to conduct further diagnostic screening.
