Shape of the cornea and conjunctiva.

An apparatus for investigating the surface shape of the eye, including the region beyond the limbus, has been developed. Formerly, we applied a three-parameter model to describe the eye profile. Recently we have found that two parameters, e.g., the keratometric radius, KE, and the slope, beta E, of the conjunctiva are sufficient for this purpose. The measurement of 690 unselected human eyes indicates that variation of both these values is statistically significant and that both of them may be useful in contact lens fitting.