The internal pressure of the eye, as important criteria in maintaining the health of the ocular tissues has always been of interest to ophthalmologists. This pressure affects the appearance of some severe visual impairment and in the process of some eye surgeries. Devices that measure this pressure are called tonometer. New experiments show that the real intraocular pressure is not the same as the measured value in any non-invasive tonometer. The most advanced tonometer is known as Corvis. A new revision of this device for intraocular pressure is the result of a statistical review of the simultaneous effect of the age and thickness of the cornea along with the amount of intraocular pressure. This corrected pressure is reported in the form of a new quantity called Biomechanical IntraOcular Pressure. The purpose of the present study is to investigate this unknown relation and to simplify it by studying the effects of the thickness and material properties on the Corvis measurement of intraocular pressure. For this purpose, an artificial anterior chamber is created and by using the contact lenses instead of the cornea on it, the effect of biomechanical properties in the tonometry process is studied experimentally. Corvis blow an air puff to the cornea to measure the pressure and takes the cross-sectional images during this procedure. To find the mechanical properties of lens materials, its deformation is calculated with the processing of these images during loading, and by using it, the hyperelastic properties of the lens were characterized by the inverse finite element method. Also, by analyzing the experimental data of the porcine cornea, it is shown that the viscoelastic behavior of these materials in this procedure is not activated. For the first time in this research, some errors are reported from, the most advanced tonometry device, which is Corvis. For this reason, in the experimental study of the tonometry process, dynamic behavior and geometric characteristics of the samples were independently calculated and processed using raw images of tests. Keywoeds: Intraocular pressure, Corvis tonometer, Central corneal thickness, Hyperelastic behavior,contact lenses, Invers finite element
