Abstract: An intraocular pressure sensor utilizes a small sensitive piezo-resistance strain gauge cell mounted in a curved semi-rigid holder which serves to position the planar pressure sensitive surface of the strain gauge cell in contact with the eyeball surface. Deformation of the strain gauge cell due to contact with the eyeball produces an output signal corresponding to the intraocular pressure. The sensor is small and can be worn in the eye like a contact lens for extended periods of time permitting the intraocular pressures to be accurately monitored under normal living conditions, including during sleep. Fine wires are led from the sensor out over the eyelid for connection to an external recording/monitoring apparatus.