The invention provides devices and methods for non-invasive monitoring and measuring of intraocular pressure (IOP) of a subject. Embodiments include a lens that is adapted to fit on the subject's eye, a microstructure disposed in or on the lens, the microstructure having at least one feature that exhibits a change in shape and/or geometry and/or position on the lens in response to a change in curvature of the lens. When the curvature of the lens changes in response to a change in IOP, a corresponding change in shape and/or geometry and/or position of the feature may be used to determine the change in IOP. The change in the feature is detectable in digital images of the lens taken with a mobile electronic device such as a smartphone.