the resistance offered by the eyeball to a change in intraocular volume; manifested as a change in intraocular pressure.
The resistance of the coats of the eye to indentation. This factor is taken into account in the tables used when determining the intraocular pressure by means of an indentation tonometer such as that of Schiötz. The tables are based on an eye of average ocular rigidity but if the eye has high or low rigidity, an error is introduced into the readings: means of minimizing this effect have been devised. See impression tonometer.