The abnormalities in the iris shape and deformation could cause closure of the space between the iris and cornea. Such closure may lead to development of certain types of glaucoma, a mysterious disease causing irreversible blindness. As such, the mechanical response of the iris and its deformation have been studied extensively in the context of glaucoma. The collagen fibrils of the iris stroma provide support while undergoing continuous large mechanical deformation. The relationship between micrometer-scale and macro-scale mechanical environment, however, remains unknown. We have used a multiscale computational framework, linking the volume-averaged stress in micrometer-scale representative volume elements to a macro-scale finite-element continuum. We fitted the multiscale model response to experimental data obtained from uniaxial tension tests of intact irides. We hope to employ our model in pathophysiological states of the iris to understand how the microscale deformation may differ in glaucomatous eyes as compared to the healthy controls.