Abstract: An applanation tonometer for measuring intraocular pressure (IOP) so that the health of a human or animal eye can be determined. The applanation tonometer includes a prism having a contact tip at one end to be moved into contact with and lightly touched against the cornea or the eye. Incident laser light is transmitted inwardly through the prism to the contact tip at which some of the light is decoupled and lost though the contact tip depending upon the area of contact between the contact tip and the cornea. The remaining light is reflected by the contact tip outwardly through the prism. A photo defector which is responsive to the light reflected by the contact tip of the prism and a force detector which is responsive to the pressure at the area of contact between the contact tip and the cornea generate paired force and area data pairs that are processed to measure IOP.

Abstract: An applanation tonometer for measuring intraocular pressure (IOP) so that the health of a human or animal eye can be determined. The applanation tonometer includes a prism having a contact tip at one end to be moved into contact with and lightly touched against the cornea or the eye. Incident laser light is transmitted inwardly through the prism to the contact tip at which some of the light is decoupled and lost though the contact tip depending upon the area of contact between the contact tip and the cornea. The remaining light is reflected by the contact tip outwardly through the prism. A photo defector which is responsive to the light reflected by the contact tip of the prism and a force detector which is responsive to the pressure at the area of contact between the contact tip and the cornea generate paired force and area data pairs that are processed to measure IOP.