Based especially on the studies of v. Frey, the anatomical, physiological and methodical fundamentals of aesthesiometrie of the cornea are considered and an electromagnetic instrument for the quantitative reproductable aesthesiometrie of the cornea is introduced. With this instrument it is shown by using various sizes of tactile probes, that the threshold value of the corneal sensitivity does not primarily depend on the size of the tactile probe, but mainly on the applied pressure. Moreover, the threshold of corneal sensitivity was measured at seventeen different points and a topographical description of the sensitivity conditions elaborated.