An ophthalmic, electrically-powered device intended to be used by a healthcare professional to measure intraocular pressure (IOP) by exerting an external force against the eye, which provides a reading of the resistance of the tunica of the eye to deformation (the extent of corneal indentation), typically for the diagnosis of glaucoma. It may have a light contact with the eye, have a bench-top or hand-held design, and use various techniques (e.g., the air-puff tonometer records deflections of the cornea from a puff of pressurized air).