A non-invasive method and system for assessing intraocular pressure (ICP) is disclosed. The method comprises the steps of measuring venous outflow pressure (VOP) using a venous ophthalmodynamometer device (vODM); measuring ophthalmic r central retinal arterial blood flow using color Doppler imaging device; and then estimating ICP using venous outflow data from the vODM and pulsatility and/or resistivity relationships derived from the Doppler imaging data. Further disclosed is a novel vODM for measuring VOP in low flow veins.