A device including an optically -transparent member having a curved front surface structured to reduce, during the measurement of internal pressure of a body that includes pressing the front surface against the shell of body, at least the measurement error caused by the presence of a fluid film between the front surface and the surface of the body (for example, a cornea) and/or the stress formed at the shell of the body during the applanation deformation of the shell and occurring at a location of the area of contact between the front surface and the shell. A method for using such device for measurement of internal pressure while determining the internal pressure with increased accuracy as compared to those obtained with the use of a flat-surfaced optically -transparent member. The curved front surface includes a first central portion and a second peripheral portion that encircles and adjoins the first central portion. The curvatures of the first and second portions have opposite signs. Specific applications and use include applanation tonometry and measurement of intraocular pressure.
