[Theoretical principles of "contactless" tonometry].
The authors present a short recapitulation of the capabilities of modern applanation tonometry and point out its limitations. They discuss the two methods, "non-contact" and "contactless" tonometry. The latter, which has been recently developed in Hungary, differs from Grolman's in that it employs an electonic system to measure the applanation, which is induced by an air jet. With this method the accuracy of the recording enables events lasting only fractions of a second to be studied in a variety of ways while measurements are being made.