Patent ID: 6413214
Filing Date: 2002-07-02
Classification: A61B

Abstract:
A tonometer comprising:an applanating element having a light-transmitting contact face engageable against the eye of a subject for projecting a light beam onto the eye and passing reflected light therefrom, means responsive to the reflected illumination and means responsive to the force of engagement of the applanating element on the eye for obtaining data of changing values of reflected illumination and force as the element is applied to the eye, said contact face having an area larger than a predetermined standard area of engagement at which the applanating force is to be determined, the instant of applanation of said predetermined standard area being obtained by interpolation from a signal obtained from the reflected illumination when the cornea is applanated over the contact face area, the instant of applanation being dependent upon the ratio of said predetermined standard and larger areas of applanation, in order to determine the force measured at said instant of applanation of the predetermined standard area.