Quantification of the mechanical properties of the iris is necessary to assess the clinical significance of passive iris deformation, which has been suggested as a mechanism for angle closure glaucoma. The animal model simulating the total pupillary block was developed to simulate angle closure glaucoma, and experiments were performed on isolated porcine irises, deformation of the iris was captured when changing the pressure difference between the posterior and anterior chamber. A simple mechanical model was used to account for the geometry of the experiment. The relationship between the area strain (6) and the pressure differences between the posterior and anterior chamber (P') is described as delta = b(0) + b(1)LnP'. Furthermore the radial 2D elastic mechanics parameter was calculated. The average 2D elastic mechanics parameter of porcine iris was found to be 5.3 N/m in the radial direction and 24.7 N/m in azimuthal direction. Experimental results provide reliable theoretical and experimental base for explanation of the blindness caused by Glaucoma. (C) 2008 Elsevier Ltd. All rights reserved.